Lista zgłoszonych abstraktów

(Tylko abstrakty zweryfikowane przez SOC)

Lp. Nazwisko (Last name) Imię (First name) Instytucja/Affilation Abstrakt1 Rodzaj Abstrakt1 Autorzy Abstrakt1 Tytuł Abstrakt1 Treść
Armiński Andrzej Polskie Towarzystwo Miłośników Astronomii Wykład/Talk Andrzej Armiński, Ryszard Siwiec Astronomia amatorska w Szczecinie: popularyzacja, edukacja i badania. Autorzy omówią działania szczecińskiego oddziału Polskiego Towarzystwa Miłośników Astronomii podejmowane w ostatnich latach w zakresie, edukacji i popularyzacji astronomii wśród różnych grup odbiorców. Przedstawione zostaną również narzędzia obserwacyjne używane przez członków PTMA o. Szczecin i przykłady badań prowadzonych za ich pomocą.
Rałowski Mateusz Jagiellonian University, Astronomical Observatory Plakat/Poster Mateusz Rałowski, Krzysztof Hryniewicz, Agnieszka Pollo Covering factor in AGNs: evolution or selection According to the Active Galactic Nuclei (AGN) unification scheme the dusty torus is an important component. The covering factor (CF) for the AGN, is defined as the ratio of infrared (IR) and bolometric luminosities. Recent studies reported the possible evolution of with redshift. This may mean the obscuration level by the torus of the black hole (BH) described by CF, changes with time. The question whether this evolution is real or the selection effects play major role is still open. The presented study tries to solve this problem. The newest SDSS photometrical and spectroscopical data from 16th data release for quasars was cross-matched with observations from GALEX, UKIDSS and WISE. From the multiwavelength photometrical observations, covering the spectrum from IR to ultraviolet (UV) the data sample of over 17 000 quasars was derived. Data was further divided into two redshift bins – low-z (from z=0.7 to 1.1) and high-z (from 2.0 to 2.4) quasars. The calculated CF median values of log10 CF(low-z)= −0.14+/-0.13 and log10 CF(high-z)= 0.10+/-0.22 may be interpreted as an evolution of CF with redshift. Based on the spectroscopic data the accreation rate was calculated. The infrared luminosity versus accretion rate relation shows clear separation between low and high redshift quasars. Finally the possible selection effects, including other methods for calculating luminosities and the selection of only objects with the best WISE signal to noise ratio, were checked.
Saraf Chandra Shekhar Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences Wykład/Talk Chandra Shekhar Saraf Cross-correlation between Planck CMB lensing potential and galaxy catalogues from HELP Cross-correlation measurements between CMB lensing and tracers of the large scale structure are a powerful probe to study the evolution of the gravitational potential and constrain cosmological models and models of structure formation. We present the first study of cross-correlation between Planck CMB lensing potential and photometric redshift galaxy catalogues from the Herschel Extragalactic Legacy Project (HELP). We improve the cross-correlation measurements by using the full available area of the CMB lensing and map and galaxy surveys, contrary to previous studies exploiting only the common area between the two. We find some deviations from the predictions of the standard cosmological model and will discuss some possible systematic errors that can account for this discrepancy.
Saha Tathagata Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences Wykład/Talk Tathagata Saha, Alex G. Markowitz, Johannes Buchner Determination of AGN torus morphology using X-ray spectra: A reliability study Several models of the X-ray reprocessing of the AGN torus have been recently released, (UXCLUMPY, CTORUS, MYTORUS etc.). They span a range of assumed torus geometries and morphologies. The degeneracies in these models can limit reliable constraints of parameters of interest, such as the intrinsic photon index and parameters determining torus morphology. To investigate these effects, we simulate synthetic data under XMM-Newton and NuSTAR response files based on six different models. We use Bayesian methods to analyze the simulated datasets with the same set of models. For exposure times and fluxes typical of nearby Compton-thick AGN, several geometrical parameters remain unconstrained. In addition, distinction of model or morphology using Bayesian methods is possible only if we have a high intrinsic value of flux for a typical exposure time. Our project aims to provide guidance for the X-ray community both in terms of the accuracy in applying the correct torus model (with implications for conclusions on the torus geometry and morphology) and the robustness of estimation of model parameters(with implications for limitations on precision of those parameters).
Sadh Mradumay CAMK,Warsaw Plakat/Poster Mradumay Sadh, Lorenzo Gavassino Extended-body corrections to the inverse-square law for spherically symmetric sources The inverse-square law for calculating the irradiation arises as a direct consequence of the conservation of the energy when spherical symmetry is imposed. The law implies that any spherically-symmetric source can be replaced, without changing the energy flux, by a point-sized source located in the center of symmetry. On the other hand, anybody who has seen a sunset knows that, when the center of the Sun moves slightly below the horizon, still a considerable portion of the stellar surface can be visible, irradiating much more than the corresponding point-sized source, which would be hidden under the horizon. This apparent contradiction is immediately solved when one realises that the presence of the planet, whose surface is absorbing part of the photon flux coming from the star, breaks the spherical symmetry, producing violations of the inverse-square in the sunset (or, equivalently, sunrise) region. On exoplanets that are extremely close to their star, this breakdown of the inverse-square law can become very important.
Rudawy Pawel Instytut Astronomiczny Uniwersytetu Wrocławskiego Wykład/Talk P. Rudawy, M. Tomczak, R. Falewicz, A. Berlicki, K. Radziszewski , K. Bicz, M. Pietras, A. Bosy ESA Programme PL_RM22 European F10.7 and F30 Monitoring System ROSIE The main foundations and objectives of the ESA’s proof of the concept project of the European network of the radio-telescopes will be presented. The observational station in Bialkow will constantly monitor and disseminate the F10.7 and F30 solar indexes (solar radio fluxes integrated over the whole disk, centered on 10.7 cm and 30 cm wavelength) and radio spectra of the same bands with very high time resolution. The semi-automatic and low-maintenance system of data collection (observations), data calibration, detection of the radio bursts in real-time, processing, and data storage will be tested.
Różański Tomasz Instytut Astronomiczny, Uniwersytet Wrocławski Plakat/Poster Tomasz Różański, Maja Jabłońska Doppler imaging and deep neural networks Doppler imaging (DI) is an effective inversion method for reconstuction of stellar surface maps. The time series of high resolution spectra used in this approach allow to infer about temperature and overabundance spots, magnetic field and non-radial pulsations. Typically, the DI problem is solved with regularized chi-square minimisation that produces solutions that fit observed variations in line profiles. Here we propose a different approach to this task based on deep neural networks (DNN). We test the method on a synthetic dataset and show that DNN models can give results comparable to traditional techniques in a much shorter time, which is important due to the rapidly increasing number of available data.
RÓŻAŃSKA AGATA Centrum Astronomiczne im. M. Kopernika PAN Wykład/Talk Agata Różańska The density of an accretion disk atmosphere We present the disk densities which outcome from vertical simulations of the accretion disk structure taking into account different processes responsible for accretions and transfer of radiation by diffusion approximation. We compare cases where the viscous tourque in standard disk is proportional to the total pressure to the case where it is proportional to the gas pressure only. In the next step, standard SS73 disk is compared to Novikov & Thorne 1973 disk with maximally spinning black hole. In yet another step, we assume that the gas in the disk is heated by magnetic reconnection (MRI). And finally, we present results from 3D GRMHD simulations of puffy accretion disks by Lancová et al. 2019. We discuss densities of an accretion disk atmospheres in those different solutions and compare them to those resulted from observations with X-ray reflection spectroscopy method.
Rosinska Dorota Uniwersytet Warszawski Plakat/Poster Dorota Rosińska, M. Szkudlarek,A. Askar,M. Giersz,T. Bulik Black holes binaries from globular clusters - the impact of a central IMBH Stellar mass binary black holes are the most important sources of gravitational waves for ground based interferometric detectors. We analyze about a thousand globular cluster (GC) models simulated using the MOCCA Monte Carlo code for star cluster evolution to study black hole - black hole interactions in these dense stellar systems that can lead to gravita- tional wave emission. We extracted information for all coalescing binary black holes (BBHs) that merge via gravitational radiation from these GC models and for those BHs that col- lide due to 2-body, 3-body and 4-body dynamical interactions. By obtaining results from a substantial number of realistic star clusters evolution model, that cover different initial pa- rameters (masses, metallicities, densities etc) we have an extremely large statistical sample of two black holes which merge or collide within a Hubble time. The existence of Intermediate Mass Black Hole strongly influences the results. We discuss the importance of BBH originating from GC for gravitational waves observations.
Riccio Gabriele Narodowe Centrum Badań Jądrowych Plakat/Poster Gabriele Riccio How reliable are galaxies physical parameters estimation for LSST main sequence sample? The upcoming Large Survey of Space and Time (LSST), conducted by Vera Rubin Observatory, will produce, over a 10-year period, multi-petabyte archive of images and catalogs of astrophysical sources on more than 18000 square degrees of the southern sky. Reaching magnitude depth of ∼ 26.5 (AB) in the six bands ugrizy, LSST data will be useful to perform a wide variety of high precision statistical studies, allowing to obtain more accurate measurements of astrophysical quantities. I will present studies based on simulated LSST observations of real galaxies in the ELAIS-N1 and COSMOS fields of the Herschel Extragalactic Legacy Project (HELP) survey. Spectral Energy Distributions (SEDs) were fitted to the real and simulated photometric measurements of 65,889 galaxies in the redshift range 0 < z < 2.5, using the latest release of a galaxy SED fitting code CIGALE. We compare main galaxy physical parameters, such as star formation rate (SFR), stellar mass and dust luminosity obtained from real data using ultraviolet and infrared observations to the same parameters obtained from the simulated optical LSST measurements only. We conclude there is a possible overestimation of SFR, dust luminosity and dust mass if they are calculated with LSST photometric measurements only. This overestimation is found to depend on redshift, diminishing up to z = 2.5. The least sensitive parameter is the stellar mass which was found to be reliably estimated even if based only on the optical bands.
Rathour Rajeev Singh Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences Plakat/Poster Rajeev Singh Rathour, Radosław Smolec and Henryka Netzel Search for non-radial mode and modulation phenomenon in Galactic Cepheids from OGLE-IV survey This work involves a detailed search for additional low-amplitude variability phenomena such as presence of non-radial mode or periodic modulation, in classical Cepheids of the Galactic fields. Previous studies on classical Cepheids have been mostly conducted in Magellanic Clouds, for such type of variability, leaving Galactic fields fairly unexplored, which forms the basis of our investigation. We perform frequency analysis of ~2000 Galactic Cepheids using the OGLE-IV photometry database. In our study, we identify ten new candidates for radial double-mode and six new candidates for radial triple-mode pulsation, extending the multi-mode radial pulsators sample. We detect, twelve first overtone Cepheids, with presence of additional variability associated with non-radial modes. This sample, when compared with the Magellanic Cloud Cepheids, depicts a systematic shift towards longer pulsation periods for more metal rich Cepheids. In the same first overtone sample, we also detect another type of additional variability, close to subharmonic frequency of the one reported above, which are the direct detection of non-radial modes. Two Cepheids out of these, show simultaneous presence of both kind of additional variability. Furthermore, we report the discovery of three modulated Cepheids, pulsating in radial fundamental mode; first overtone and a combination of both, respectively. The latter double-mode Cepheid, in which only the fundamental mode is modulated, is the very first detection of periodic modulation in this pulsation type.
Przerwa Michał Physics Department, University of Warsaw and Center for Theoretical Physics PAS Plakat/Poster Agnieszka Janiuk, Michał Przerwa Analyzing time-dependent neutrino accretion disc in Gamma-Ray Bursts The goal of this work is to analyze the conditions inside accretion disc using a 1-D model that includes the condition of beta-equilibrium and neutrino cooling. Such conditions are adequate for the central engine that powers relativistic jets in Gamma Ray Bursts.
Skorek Ewa University of Warsaw Plakat/Poster Ewa Skorek, Swayamtrupta Panda Revealing the cosmic evolution of quasars using metallicity indicators Broad-band spectra of active galaxies contain a wide range of information that help reveal the nature and activity of the central continuum source and their immediate surroundings. Understanding the evolution of metals in the Active Galactic Nuclei (AGN) spectra and linking them with the various fundamental black hole (BH) parameters, for example, BH mass, the bolometric luminosity of the source, its accreting power, can help address the connection between the growth of the BH across cosmic time. We investigate the role of selected metallicity indicators utilizing the rich spectroscopic database of emission lines covering a wide range in redshift in the Sloan Digital Sky Survey’s recent spectroscopic data release. We make careful filtering of the parent sample to prepare a pair of high-quality, redshift-dependent sub-samples and present the first results of the analysis here. To validate our findings from the simple correlations, we execute principal component analysis (PCA) over our sub-samples and present the 3D projection maps here which highlight the primary drivers of the observed correlations. The projection maps also allow us to isolate peculiar sources of potential interest.
Prince Raj Center For Theoretical Physics, PAN, Warsaw, Poland Wykład/Talk Raj Prince, Krzysztof Hryniewicz, Swayamtrupta Panda, Bożena Czerny, Agnieszka Pollo Viewing angle observations and redshift evolution in quasar based cosmology This talk will focus on the observational measurement of the viewing angle of individual quasars by modeling the broadband quasar spectrum ranging from the infra-red (IR) to the soft X-ray band. Sources are selected from various published catalogs, and their broadband quasi-simultaneous spectral data points were collected and used to model. We started with a COSMOS sample of type-1 sources which have broadband photometric points. Then, to include more data points, we cross-matched the COSMOS with the SDSS DR14 quasar catalog, and eventually, we find 90 sources that have broadband data ranging from IR to soft X-ray. The broadband spectral energy distribution (SED) modeling is done in Xspec by using the optxagnf and the SKIRTOR models for the X-ray, UV, Optical, and IR regimes for each source. The whole sample is divided into four bins with respect to redshift, black hole (BH) mass, and Eddington ratio with an equal number of sources in each bin. The viewing angle is estimated in each bin, and its evolution with respect to redshift, BH mass, and Eddington ratio is examined. As a result, we did not find any significant evolution of viewing angle with those parameters within the 95% confidence interval. We conclude that the use of quasars in cosmology to determine the expansion rate of the universe is therefore justified, and biases are not expected.
Posiłek Natalia Instytut Astronomiczny, Uniwersytet Wrocławski Plakat/Poster Ewa Niemczura, Natalia Posiłek Spectroscopic observations of chemically peculiar Am candidates observed by TESS satellite. In recent years we have collected a big sample of high-resolution and high-signal-to-noise spectra of chemically peculiar bright Am stars observed by the TESS mission. The detailed analysis of these spectra will allow us to properly classify these stars and to determine their atmospheric parameters, chemical composition, and projected rotational velocities. We will also identify spectroscopic double-lined binary stars in our sample. This information is necessary to fully understand the TESS satellite observations. The precise photometric time series gathered by TESS will help us answer several questions regarding the incidence of pulsations in Am stars, dependence of pulsation characteristics on atmospheric parameters, chemical abundances, and projected rotational velocities. Moreover, the analysis of the TESS photometric data supplemented with the results of spectroscopic analysis are the necessary ingredients of stellar seismology, the only method allowing us to understand the inner structure of a star.
Porowski Czesław CBK Wykład/Talk C. Porowski, M. Bzowski A new 3D solar wind speed and density models based on interplanetary scintillations. A model of solar wind and density spatial distribution and its time variations during the recent decades is a starting point in many areas of heliosphere research. In-situ measurements of solar wind parameters have been performed since the beginning of the space age, but they refer to the solar equator only. Although the Ulysses mission performed in-situ measurements of solar wind parameters at high heliolatitudes, continuous in-situ measurements at high heliolatitudes are not available. In order to fill the gaps in the continuous solar wind speed and density in-situ measurements at high latitudes of the sun, interplanetary scintillations (IPS) are used for estimation of the desired solar wind parameters. The IPS data are provided in the form of Carrington speed maps, obtained using the tomographic technique. Their overall usefulness was demonstrated by comparing of the IPS speed profiles at high heliolatitudes with the Ulysses data. However, the Carrington speed maps suffer from insufficient coverage of observations during the year, as well as from points with unrealistic values, which contribute to undesirable background. During determination of the average solar wind speed profile, the background points accumulate and affect the obtained results. In order to avoid introducing of possible bias due to the background, a special treating during determination of the mean yearly profiles of solar wind was developed. Therefore, in the talk some technical aspects of the new model of the solar wind speed will be presented. Also, the methodology and results of the solar wind density estimation during the last three solar cycles will be shown.
Poleski Radosław Obserwatorium Astronomiczne, Uniwersytet Warszawski Wykład/Talk R. Poleski Wide-orbit exoplanet occurrence rate Exoplanets that do not orbit any star, or free-floating exoplanets, are some of the most intriguing astronomical objects. Candidate free-floating exoplanets are discovered using gravitational microlensing technique as very short events that show only a single lens. In order to verify if these candidates are truly free-floating we should consider an alternative interpretation, i.e., that the event is caused by a bound exoplanet on a wide orbit and by chance the signal from the host is not detected. I will present the most recent estimate of occurrence rate of wide-orbit exoplanets (i.e., similar to Uranus and Neptune) with masses smaller than a few Jupiter masses. I will also show a method to derive the occurrence rate that takes into account the uncertainties of each object parameters.
Pistis Francesco NCBJ Wykład/Talk Francesco Pistis, Agnieszka Pollo, and VIPERS team The Fundamental Metallicity Relation from SDSS (z~0) to VIPERS (z~0.7): selection or evoltion? Galaxy metallicity, as result of the integrated star formation history and evolution of the interstellar medium, is an important property describing galaxy evolution. Using the data from the Sloan Digital Sky Survey (SDSS), it has been widely studied in the local Universe as well as its relation with galaxy stellar mass and star formation rate (SFR). The relation between these three galaxy physical properties, known as Fundamental Metallicity Relation (FMR), was shown not to undergo any significant evolution at least up to z~2. Despite that, different studies find some differences in 2D projections of this relation. However, these studies are based on very different samples, with different data selection at different redshift range. In our work we aim to find FMR evolution from z~0.7 to z~0, making use of the unprecedented statistics of the VIMOS Public Extragalactic Survey (VIPERS) and comparing it to the local SDSS sample. Having this goal in mind, we study the effects of different selection biases introduced into the SDSS sample on both the FMR and its 2D projections. We find significant differences occuring when different data selections, simulating the selection of higher redshift samples, are applied. Then, we compare these results with the data from the VIPERS sample at z~0.7. We conclude that both FMR and its projections at z~0.7 and z~0 are not in complete agreement even when the data selection effects are carefully applied. This implies a small but statistically significant evolution of the FMR between z~0.7 and z~0 which needs to be taken into account in future studies.
Pilecki Bogumił Centrum Astronomiczne im. M. Kopernika PAN Wykład/Talk Bogumił Pilecki Revealing a Numerous Population of Double-lined Binary Cepheids Masses of classical Cepheids of 3-11 M⊙ are predicted by theory but those measured clump between 3.6-5 M⊙. As a result, their mass-luminosity relation is poorly constrained, impeding our understanding of basic stellar physics and the Leavitt Law. All Cepheid masses come from the analysis of 11 binary systems, including only five that are double lined and well suited for accurate dynamical mass determination. We present a project to analyze a new, numerous group of Cepheids in double-lined binary (SB2) systems to provide mass determinations in a wide mass interval and study their evolution. We analyzed a sample of 41 candidate binary LMC Cepheids spread along the P-L relation, which are likely accompanied by luminous red giants, and present indirect and direct indicators of their binarity. In a spectroscopic study of a subsample of 18 brightest candidates, for 16 we detected lines of two components in the spectra, already quadrupling the number of Cepheids in SB2 systems. Our project paves the way for future accurate dynamical mass determinations of Cepheids in the LMC, Milky Way, and other galaxies, which will potentially increase the number of known Cepheid masses even 10-fold.
Pietras Małgorzata Instytut Astronomiczny UWr Plakat/Poster Małgorzata Pietras, Robert Falewicz, Marek Siarkowski, Kamil Bicz Analysis of stellar flares observed with TESS We present the results of the analysis of stellar flares based on TESS observations. We used the two-minute cadence data obtained from sectors 1-38. Our software allows us to identify flares and determine its basic parameters such as: amplitude, duration, growth and decay times. We estimate the total energy of flares in two different methods. We investigate distributions of flare frequencies and its dependence upon spectral types. we already identified about 130 000 flares from more than 23 000 flaring stars from F-type to M-type. From the analysis we conclude that approximately 7.5% of all observed stars show flaring activity, which is in agreement with other papers on this topic. Based on bolometric flare energy estimations, we conclude that its energies range from 10^31 to 10^36 erg, with an average energy of 10^33 erg. The result of the performed analysis is also the statistical distribution of the parameters of flaring stars.
Pearson William Nation Centre for Nuclear Research Plakat/Poster William J. Pearson Understanding real galaxy mergers through simulations and deep learning Galaxy mergers are events that underpin how our Universe grows and evolves. Despite their importance, knowing exactly what is and is not a real galaxy merger is not as simple as it seems. Equally, knowing how far along in a merger is for real galaxy mergers is a non-trivial issue, beyond a simplistic pre-coalescence, coalescence and post-coalescence categorisation. Due to the long times scales involved, on the order of a billion years, we cannot wait and watch mergers occur and evolve to solve these issues. Thus, merger detections can be uncertain and it is difficult to follow the physical processes inside mergers as a merger progresses. Simulations do not have these problems. Zoom in simulations allow us to closely follow two colliding galaxies and observe how physical properties change and evolve. Cosmological simulations allow us to gather a large number of known galaxy mergers for statistical samples. Thus, being able to use simulations with known truths of if a galaxy is a merger and known times before or after a merger event to identify and classify galaxy mergers would be an incredibly powerful tool. During this talk, I will discuss how we can take the images and truths from simulations and apply them to the real Universe through deep learning. We will see how this can allow us to gain a base truth for what is a merger and identify how far along real mergers are. This will also be explored through the use of observationally trained neural networks to help understand the kind of data we need from the simulated galaxies to train networks for application to real data. From this, we can have a sneak peak at the kind of science that is right around the corner using these cutting edge techniques.
Panda Swayamtrupta Center for Theoretical Physics, Polish Academy of Sciences Plakat/Poster Swayamtrupta Panda, Alberto Rodriguez-Ardila A novel black hole mass scaling relation based on coronal gas and its connection with the accretion disc Coronal lines (CLs) or forbidden high ionization emission lines originate from forbidden fine structure transitions excited by collisions in highly ionized species (ionization potential, IP $>$ 100 eV). Because of their very high ionization potential, they are considered to be a reliable signature of the presence of an active galactic nucleus (AGN) in galaxies. Using bonafide black hole (BH) mass estimates from reverberation mapping and the line ratio [Si VI]$sim$1.963$mu$m/Br$gamma_{rm{broad}}$ as tracer of the AGN ionising continuum, a novel BH-mass scaling relation of the form $log (M_{rm{BH}})$ = (6.40$pm$0.17) - (1.99$pm$0.37)$times log$([Si VI]/Br$gamma_{rm{broad}})$, over the BH mass interval, $10^6 - 10^8$ M$_{odot}$ with dispersion 0.47 dex is found. Following on the geometrically thin accretion disc approximation and after a detailed survey of the physical parameter space for coronal lines (CL) production, the effective temperature of the accretion disc is found to be the primary driver of the strength of the [Si VI]$sim$1.963$mu$m coronal line for the range of BH masses considered.
Sethi Sagar Obserwatorium Astronomiczne Uniwersytetu Jagiellońskiego Plakat/Poster Sagar Sethi, Marek Jamrozy, Agnieszka Kuźmicz Multiwavelength radio analysis of 2 Mpc – size radio galaxies. Abstract: A giant radio galaxy (GRG) is an extreme type of active galaxy that has radio jets of a size larger than 0.7 Mpc. Most of the known GRGs are of FRII type whose jets remain laminar and relativistic throughout their whole journey in a single phase of activity. How some radio galaxies evolve to such a large scale is still an unsolved mystery. The size of GRGs depends on mostly three factors, i.e. IGM density, jet power, and age of the source. It was believed that GRGs are born in a sparse environment. However, some GRGs were also found in clusters of galaxies. To determine the jet power and age of the largest GRGs it is crucial to analyze multi-frequency radio maps of proper uv-coverage, angular resolution, and sensitivity. In this poster, we present the radio properties of a 2 Mpc size GRG from our sample.
Skowron Dorota Obserwatorium Astronomiczne, Uniwersytet Warszawski Wykład/Talk Dorota Skowron & OGLE Reddening Maps of the Large and Small Magellanic Cloud based on OGLE-IV Red Clump Stars I will present the most extensive and detailed reddening maps of the Magellanic Clouds derived from the color properties of Red Clump stars. The analysis is based on the deep photometric maps from the fourth phase of the Optical Gravitational Lensing Experiment (OGLE-IV), covering approximately 670 deg2 of the sky in the Magellanic System region. We refined methods of calculating the RC color to obtain the highest possible accuracy of reddening maps based on RC stars. Using spectroscopy of red giants, we found the metallicity gradient in both MCs, which causes a slight decrease of the intrinsic RC color with distance from the galaxy center of about 0.002 mag/deg in the LMC and between 0.003 and 0.009 mag/deg in the SMC.
Olejak Aleksandra CAMK PAN Wykład/Talk Aleksandra Olejak, Krzysztof Belczynski, Natalia Ivanova Impact of common envelope development criteria on the formation of LIGO/Virgo sources The treatment and criteria for development of unstable Roche lobe overflow (RLOF) that leads to the common envelope (CE) phase have hindered the area of evolutionary predictions for decades. In particular, the formation of black hole-black hole (BH-BH), black hole-neutron star (BH-NS), and neutron star-neutron star (NS-NS) merging binaries depends sensitively on the CE phase in classical isolated binary evolution model. All these mergers are now reported as LIGO/Virgo sources or source candidates. CE is even con- sidered by some as a mandatory phase in the formation of BH-BH, BH-NS, or NS-NS mergers in binary evolution models. At the moment, there is no full first-principles model for the development of the CE. We employed the StarTrack population synthesis code to test the current advancements in studies on the stability of RLOF for massive donors to assess their effect on the LIGO/Virgo source population. In particular, we allowed for more restrictive CE development criteria for massive donors (M > 18 M ). We also tested a modified condition for switching between different types of stable mass transfer and between the thermal or nuclear timescale. The implemented modifications significantly influence the basic properties of merging double compact objects, sometimes in non-intuitive ways. For one of the tested models, with restricted CE development criteria, the local merger rate density for BH-BH systems increased by a factor of 2-3 due to the emergence of a new dominant formation scenario without any CE phase. We find that the changes in highly uncertain assumptions on RLOF physics may significantly affect: (i) the local merger rate density; (ii) shape of the mass and mass ratio distributions; and (iii) dominant evolutionary formation (with and without CE) scenarios of LIGO/Virgo sources. Our results demonstrate that without sufficiently strong constraints on RLOF physics, it is not possible to draw fully reliable conclusions about the population of double compact object systems based on population synthesis studies.
Śniegowska Marzena Nicolaus Copernicus Astronomical Center Polish Academy of Sciences Plakat/Poster M. Śniegowska, S. Panda, B. Czerny The usefulness of spectropolarimetry for NLSy1. Some of Narrow Line Seyfert 1 galaxies are considered to be very high Eddington ratio sources. However, black hole mass measurement based on unexpectedlyshort time lags seen in the reverberation mapping (RM) campaigns are found tobe smaller, although uncertain. We used Very Large Telescope spectropolarimetric observations of 3 NLSy1 galaxies to measure their inclination and black hole mass from the wavelength-dependent polarization angle at the Halpha region. Upon completion, we will have estimates for the viewing angle and the black hole mass in these sources and this will be tested against polarisation radiative transfer code STOKES, which lets us to simulate radiative transfer in different geometries for emitting and scattering structures.
Ziółkowska Oliwia Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences Plakat/Poster Oliwia Ziółkowska, Ksenia Suchomska, Cezary Gałan, Radosław Smolec Estimating mass-loss rate in low-mass, evolved eclipsing binaries We use freely available parsec isochrones to determine evolutionary stages of low-mass eclipsing binaries in the Galactic Bulge. For each system, we look for an isochrone that best fits both components in the parameter space of temperature, luminosity, and mass. Canonical models predict almost equal masses of the stars at the stages after the main sequence. A moderate rate of mass loss must be included in the evolution to reproduce the position of components in the mass-temperature and mass-luminosity diagrams. The bigger the mass ratio of the system, the higher mass-loss rate is needed.
Ziolkowski Janusz Copernicus Astronomical Center Wykład/Talk Janusz Ziolkowski Obituary of Schonberg-Chandrasekhar limit We present a comprehensive description of the Schönberg-Chandrasekhar (S-C) transition, which is an acceleration of the stellar evolution from the nuclear to the thermal time scales occurring when the fractional mass of the helium core reaches a critical value, i.e. about 0.1. It occurs in the 1.4-7 M⊙ mass range due to impossibility of maintaining the thermal equilibrium after the nuclear energy sources in the core disappear. We confirm that a sharp S-C limit is present for strictly isothermal cores, but the phenomenon is much smoother for real stars (S-C transition rather than S-C limit). We found that the S–C transition does not correspond to a sharp limit but instead occurs in an extended range of the fractional core mass, of 0.03 to 0.11. Therefore, it is difficult to single out a specific value of the fractional core mass and define it as the S–C limit. We have considered whether the S-C limit can be used as a diagnostic constraining the evolutionary status of accreting X-ray binaries, but found such uses unfounded.
Zieliński Paweł Astronomical Observatory, University of Warsaw Wykład/Talk P. Zieliński, Ł. Wyrzykowski, P. Mikołajczyk, M. Jabłońska, K. A. Rybicki, M. Kałuszyński Black Hole TOM - new automatic tool for time-domain astronomy In the era of large sky photometric surveys, rapid and reliable processing of CCD images plays crucial role in characterising transient phenomena. The Black Hole Target Observation Manager (BHTOM) is a new tool based on Las Cumbres Observatory's TOM, developed under OPTICON H2020 programme for managing the observations of time-domain targets based on alerts from surveys like Gaia, ZTF or ASAS-SN. One of the most important features of BHTOM is an automatic calibration of photometric FITS images in order to obtain science-ready data points on light curves of observed targets. The system can be used to combine multiwavelength photometric data from multiple telescopes and instruments within minutes from observations. Therefore, the tool can be widely used for a variety of time-domain applications. We present the status of BHTOM, its main capabilities and application to black hole search among gravitational microlensing events.
Wyrzykowski Lukasz Astronomical Observatory, University of Warsaw Plakat/Poster Łukasz Wyrzykowski, Katarzyna Kruszyńska, Krzysztof Rybicki, Paweł Zieliński, Mariusz Gromadzki Black Hole hunt in microlensing events from Gaia Alerts and DR3 Gaia space mission has been scanning the whole sky since 2014. It has been informing the astronomical community about transient events, such as supernovae or microlensing events via Gaia Science Alerts system. Such events has been extensively studied using ground-based follow-up observations, both photometric and spectroscopic, using a broad range of instruments, from a network of small telescopes to the largest instruments, e.g. ESO or SALT. We have discovered and studied in detail tens of microlensing events potentially hosting black hole lens. Apart from the alerts, the forthcoming Gaia Data Release 3 (DR3) will contain a catalogue of past microlensing events, for which Gaia will provide super high accuracy astrometric time-series. A combination of astrometry and photometry will yield mass and distance determination for the lenses, hence a recognition of the black holes in the Milky Way, complementing the picture of black holes seen so far from X-ray binaries and Gravitational Waves.
Wrona Marcin Astronomical Observatory, University of Warsaw Plakat/Poster M. Wrona, M. Ratajczak, P.A. Kołaczek-Szymański, S. Kozłowski, I. Soszyński, P. Iwanek, A. Udalski, M. K. Szymański, P. Pietruko One thousand heartbeat stars in the OGLE collection of variable stars Heartbeat stars (HBSs) are a subclass of the ellipsoidal variables with an eccentric orbit. Brightness variations of those systems are caused mainly by tidal deformation of at least one component, and they are most clearly visible near the periastron passage. The name of this type of variable stars refers to the most characteristic shape of the light curve, which is similar to an electrocardiogram signature. We present the results of searching for HBSs in the OGLE project database. We classified a sample of 996 candidates of those systems, which increases the number of officially cataloged HBSs fivefold. The sample consist of two groups of HBSs with different physical properties. The main difference between the two groups is an evolutionary status of the primary. The first group of about 100 systems contains a hot main sequence or a Hertzsprung gap primary, while the second group of about 900 systems includes a red giant star.
Wójtowicz Anna Obserwatorium Astronomiczne Uniwersytetu Jagiellońskiego Wykład/Talk Wójtowicz A., Stawarz Ł., Machalski J., Ostorero L. How to Estimate the Ambient Medium Density Around Distant Radio Sources from Their Observed Radio Spectra Here we present our analysis of a dataset, consisting of the physical parameters derived from an extensive modeling of the largest currently available sample of FRII radio sources, for which good-quality multi-wavelength radio flux measurements could be collected. In the analyzed dataset, we notice a significant and non-obvious correlation between the spectral index of the non-thermal radio emission continuum, and density of the ambient medium. We propose that the discovered correlation could be used as a cosmological tool to estimate the density of ambient medium for large samples of distant FRII radio galaxies. Our method does not require any detailed modeling of individual sources, and relies on limited observational information, namely the slope of the radio continuum between the emitted frequencies 0.4GHz and 5GHz, possibly combined with the total linear size of the radio structure.
Włodarczyk Ireneusz Polskie Towarzystwo Astronomiczne/Polskie Towarzystwo Miłośników Astronomii Plakat/Poster Ireneusz Wlodarczyk Non-gravitational parameters of comet 2I/Borisov We computed the non-gravitational parameters of the comet 2I/Borisov for different astrometric error models. We used all 3092 optical observations from 2018 December 13.47655 to 2020 April 28.447219. According to the JPL Small-Body Database website ($#$top), the comet 2I=C/2019 Q4 (Borisov) belongs to the Hyperbolic Comet, i.e. it is a comet on hyperbolic orbit (eccentricity, e>1.0). To compute the orbit of comet 2I/Borisov, we first selected and weighting observations using Bielicki and Sitarski method. Next, we used the OrbFit 5.0.7 software with the NASA JPL DE431 ephemerides, weighting and selecting observations according to the Near-Earth Objects Dynamic Site, the error model 'fcct14'. We also used the error model 'vftc17'. There are computed non-gravitational parameters with the 'vfcc17' error model: A1=(1.9395E-07 +/- 1.9187E-07) au/d^2 A2=(8.7274E-07 +/- 4.3710E-07) au/d^2 A3=(3.2486E-08 +/- 1.2788E-07) au/d^2 We showed that using the Bielicki and Sitarski method of selection and weighting observations with the NEODys methods and the error models 'fcct14' and 'vfcc17' implemented in the OrbFit software give precious orbit of 2I/Borisov comet. We computed that the error model 'vftc17' gives better results than the 'fcct14' because of the smaller number of rejected observations and smaller RMS of fitted orbit. The value of non-gravitational parameters A1, A2, and A3 strongly depend on the error model used.
Wielgus Maciek Black Hole Initiative, Harvard University Wykład/Talk Maciek Wielgus Event Horizon Telescope I will give an overview of the Event Horizon Telescope project, results published so far and the future perspectives.
Tokarek Jakub Instytut Obserwatorium Astronomiczne, Uniwersytet im. Adama Mickiewicza w Poznaniu Plakat/Poster Jakub Tokarek Poszukiwanie układów hierarchicznych w katalogu Gaia EDR3 Układy podwójne i wielokrotne stanowią większość obserwowanych gwiazd - ponad 50% gwiazd w okolicach Słońca pozwala zakładać, że podobna sytuacja zachodzi w całej Galaktyce. Zarówno obserwacje, jak i symulacje pokazują, że wszystkie gwiazdy na początku swojej ewolucji mają jednego lub więcej towarzyszy. Powstają one podczas zapadania się obłoków molekularnych - jeden obłok zagęszcza się niezależnie w wielu miejscach, dzięki czemu powstaje gromada gwiazd. Zależnie od wzajemnej odległości między nimi są one bardziej lub mniej związane grawitacyjnie ze swoimi sąsiadami. Dzięki misji Gaia z każdą kolejną porcją opublikowanych danych jesteśmy w stanie coraz dokładniej poznawać położenia i prędkości gwiazd. W swojej pracy wykorzystałem Gaia Early Data Relase 3 do wyszukania potencjalnych towarzyszy wizualnych znanych układów wielokrotnych z "Light time effect" (LITE - efekt opisujący różnicę pomiędzy obserwowanymi a oczekiwanymi - wyliczonym na podstawie modelu - czasami zaćmień w układzie zaćmieniowym). Biorąc jako punkt wyjśca katalog 240 układów zaćmieniowych z efektem LITE (Zakiirov, 2010) odnalazłem 50 kandydatów na składniki wizualne tychże układów. W kolejnych krokach zaplanowane zostały próby wyznaczania orbit składników wizualnych oraz analiza statystyczna danych.
Szubiakowski Jacek Olsztyńskie Planetarium i Obserwatorium Astronomiczne Wykład/Talk Jacek Szubiakowski A novel gaze on the Nicolaus Copernicus' Commentariolus The talk provides a new overview of the brief manuscript “Nicolai Copernici de hypothesibus motuum coelestium a se constitutis commentariolus”. In it, Copernicus, avoiding mathematical complexity outlined his innovative concept. The paper came into being not long after the moment of a genius illumination, in which Copernicus perceived the path leading to a new order of the Universe. The time of its creation coincides with Copernicus' stay at the bishop's castle in Lidzbark Warmiński, where he came in the fall of 1503. Although, he never mentioned when he made his crucial discovery and how it came to him. Yet, it is probable that it happened during his stay in Lidzbark. It is especially interesting in the context of the recent discovery of the related inscription on the wall of the castle's cloister. The talk is an attempt to reconstruct the thought process that could guide Copernicus to his final version of the heliocentric model.
Słowikowska Agnieszka Instytut Astronomii Plakat/Poster Aga Słowikowska (1), A. Sybilska (2), S. Kozłowski (3), A. Shearer (4), A. Gurgul (2,5), S. Hus (2), P. Zieliński (5); (1) Insti NEOPol: Polish polarimeter for NEOs – first light and first results NEOPol is a prototype polarimeter built for the European Space Agency (ESA) to monitor Near-Earth Objects (NEOs). The project's primary goal is to measure the polarization degree as a function of phase angle. With this information, we can obtain an object's albedo and subsequently determine the corresponding asteroid class. The instrument's first light and tests were performed at the 60-cm Cassegrain telescope at the Institute of Astronomy of the Nicolaus Copernicus University in Toruń, Poland. Our presentation shows the first results based on the observations of highly polarized and low polarized standard stars obtained in July 2020 and February 2021. We reach the expected accuracy level of 0.1 % for the linear polarization degree and from 0.5 to 4 degrees for the position angle. NEOPol will ultimately be mounted at the 1-m ESA Optical Ground Station Telescope at the Observatorio del Teide in Tenerife.
Szaforz Żaneta Centrum Badań Kosmicznych, PAN Plakat/Poster Żaneta Szaforz, Tomasz Mrozek Quasi-periodic pulsations visible in the STIX light curves Quasi-periodic pulsations (QPPs) - nearly periodic changes of intensity in the electromagnetic radiation, have been encountered in almost all energies during many flares. The most pronounced observations come from the hard X-ray (HXR) and microwave radiation, where the quasi-periodic changes are often very clear, with the periods of oscillations varying from fractions of a second to tens of minutes. STIX, recently launched hard X-ray imaging spectrometer, is a new source of information about QPPs. We present examples of QPPs observed during solar flares registered by the STIX instrument.
Sylwester Barbara Centrum Badań Kosmicznych PAN Plakat/Poster B. Sylwester, J. Sylwester, K.J.H. Phillips and A. Kępa O obfitości wapnia podczas faz zaniku rozbłysków słonecznych Używając nowych danych o kalibracji spektrometru z wypukłymi kryształami BCS (Bent Crystal Spectrometer na pokładzie Solar Maximum Mission) wyznaczono z dużą dokładnością obfitości absolutne wapnia. Obfitości wyznaczano analizując wartość emisji w liniach jonu Ca XIX względem poziomu sąsiedniego kontinuum. Zarówno obserwowane linie jak i kontinuum formują się w źródłach (rozbłyskach) o temperaturze T > 5 MK. Stwierdzono, że dla większości spośród przebadanych 207 faz zaniku rozbłysków obfitość wapnia jest stała w granicach niepewności pomiaru (1 - 3%), jednak dla kilku zjawisk widać wyraźne zmiany obfitości. Przedstawimy uzyskane wyniki oraz zaproponujemy możliwe scenariusze fizyczne objaśniające obserwowane zmiany obfitości.
Sylwester Janusz Centrum Badań Kosmicznych PAN Wykład/Talk J. Sylwester, B. Sylwester, K.J.H. Phillips and A. Kępa Dokładne wyznaczenia absolutnych obfitości wapnia w plazmie rozbłysków słonecznych Jednym z przyrządów rejestrujących widma rentgenowskie rozbłysków z pokładu obserwatorium NASA Solar Maximum Mission (SMM) był Spektrometr z Wypukłymi Kryształami -BCS (Bent Crystal Spectrometer). Spektrometr ten zarejestrował setki tysięcy, jak dotychczas najlepszych, widm obejmujących okolice linii emisyjnych helo-podobnych jonów Ca i Fe. W pierwszym kanale obserwowano tzw. tryplet linii Ca XIX wraz z sąsiadującymi liniami satelitarnymi powstającymi wskutek rozpadu stanów podwójnie wzbudzonych w jonach Ca XVIII. Linie emisyjne obserwowane były ponad kontinuum formującym się w procesach hamowania i rekombinacji promienistych. Wkład światła rozproszonego i fluorescencji był – co osiągnięto po raz pierwszy – do zaniedbania. Spektrometr BCS, prowadzący obserwacje w okresie 1980 -1989 wyposażony był w kolimator wydzielający z promieniowania całej tarczy emisję wybranego obszaru aktywnego. Jednoczesna, dzięki wypukłości kryształu rejestracja linii emisyjnych i kontinuum umożliwia określenie obfitości pierwiastka wapnia w sposób absolutny – względem wodoru. (Obfitość protonów odpowiedzialna jest za promieniowanie hamowania a obfitość wapnia za promieniowanie w liniach). W wyniku początkowej analizy, przeprowadzonej wkrótce po starcie SMM, wyznaczono obfitości wapnia (ACa) dla 146 zjawisk odkrywając, że obfitość wapnia różni się znacznie pomiędzy poszczególnymi rozbłyskami. Obecnie dokonaliśmy ponownej analizy widm BCS dla 207 fazy zaniku rozbłysków obserwowanych w trakcie całej Misji. W analizie wykorzystano nowe dane o kalibracji spektrometru. Zastosowanie współczesnych obliczeń atomowych i nowego podejścia umożliwiło wyznaczenie obfitości Ca z nienotowaną dokładnością 1-3 % dla niektórych zjawisk. W referacie przedstawimy elementy nowego podejścia do problemu w powiązaniu z nowym procesem redukcji widm oraz porównamy wyniki uzyskane obecnie z tymi sprzed ~30 lat (53 wspólnych zjawisk) oraz przedyskutujemy zmienność obfitości wapnia dla zjawisk obserwowanych w trakcie prawie pełnego cyklu aktywności.
Sureshkumar Unnikrishnan Astronomical Observatory of the Jagiellonian University Wykład/Talk Unnikrishnan Sureshkumar Galaxy properties as tracers of galaxy clustering Galaxies live in dark matter haloes and hence the galaxy properties are majorly defined by the properties of the haloes. Hence, the environmental dependence of dark matter halo properties prompt a correlation between galaxy properties and the environment. In this talk, I will discuss the results from our recent study about how different galaxy properties such as luminosities in u, g, r, J, K-bands, stellar mass, and star formation rate trace the galaxy clustering, and hence the environment. We use a set of stellar mass selected galaxy samples from the Galaxy and Mass Assembly (GAMA) survey. We measure the two-point correlation function and marked correlation functions using the aforementioned properties as marks. We show that the stellar mass is the most reliable tracer of small-scale galaxy clustering. We also discuss the caution to be taken while using K-band as a proxy to stellar mass and u-band as a proxy to star formation rate in the context of galaxy clustering. This work has been accepted in A&A and can be found at I will also discuss the results from the ongoing study that extends the analysis to infrared bands.
Sur Ankan Nicolaus Copernicus Astronomical Center Wykład/Talk Ankan Sur Magnetic field evolution in neutron stars from MHD simulations An open question still exists in studying the neutron star’s magnetic field structure as to what energies are stored within the poloidal and toroidal components. We present MHD and GRMHD simulations of the magnetic field evolution in neutron stars to study the different dynamics such as the poloidal and toroidal field energies, growth times of the various instability-driven oscillation modes and the phenomena of turbulence. For both initially predominantly poloidal and toroidal fields, with varying strengths, we find that the field settles down to a mixed poloidal-toroidal configuration, where the toroidal component contributes between $10%$ and $20 %$ of the total magnetic energy. This is, however, not a strict equilibrium, as the instability leads to the development of turbulence, which in turn gives rise to an inverse helicity cascade, which determines the final ``twisted torus'' setup. The final field configuration is thus dictated by the non-linear saturation of the instability, and is not stationary. The average energy of the poloidal and toroidal components at earlier stages is approximately stable in our simulations, and a complex multipolar structure emerges at the surface, while the magnetic field is dipolar at the exterior boundary, outside the star. However, at later times, we find that the magnetic energy decreases significantly and the turbulence doesn’t follow the Kolmogorov law.
Stawarz Łukasz Obserwatorium Astronomiczne, Uniwersytet Jagielloński Wykład/Talk Łukasz Stawarz High-Energy View on Evolving Galaxies and Their Nuclei All massive galaxies contain supermassive black holes (SMBHs) in their centres, and the growth of SMBHs and the cosmological evolution of galaxies are tightly connected: during the galaxy merger events, accreting gas triggers starbursts, and at the same time feeds SMBHs and fuels their activity. Through powerful winds from black hole accretion disks, and relativistic jets produced via extraction of a rotational energy of a spinning black hole, SMBHs respond to this fuelling in a complex feedback loop, that couples the energy output of active galactic nuclei (AGN) to the surrounding matter available for the accretion and starformation. In this way, AGN are now recognized as a fundamental component of all the models of galaxy evolution. Indeed, there are growing observational evidence for dramatic interactions between AGN jets and their environment, i.e. for the jets driving outflows in the interstellar medium of host galaxies, as well as raising the central entropy and heating of the intracluster gas in groups and clusters of galaxies. And while the evolution of stars and dust in galaxies is imprinted in the extragalactic background light at optical and infrared frequencies, the mass and spin distribution of co-evolving SMBHs may be imprinted in the cosmic background emission at radio, X-ray, and gamma-ray photon energies, through the broad-band radiative output of AGN accretion disks and jets.
Stachowski Grzegorz Obserwatorium na Suhorze Plakat/Poster W. Ogłoza, G. Stachowski, B. Zakrzewski. M. Żejmo TIDAK: the updated Suhora database of O-C diagrams and elements of eclipsing binary stars The database of minima, O-C diagrams and linear elements of eclipsing binary stars maintained at the Mt. Suhora Observatory of the Cracow Pedagogical University in Poland is widely referenced in eclipsing binary studies. Here we present the latest version of the database, along with a new, graphical interface including features such as interactive O-C diagrams. This is the final result of an extensive modernisation program aimed at making the database more useful and convenient for researchers and observers.
Soszyński Igor Obserwatorium Astronomiczne Uniwersytetu Warszawskiego Wykład/Talk Igor Soszyński The phenomenon of long secondary period in red giants Long secondary periods (LSPs), observed in a third of pulsating red giant and supergiant stars, are the only unexplained type of large-amplitude stellar variability known at this time. Numerous authors have explored various scenarios for the origin of LSPs, but were unable to give a final solution to this problem. I will present known properties of LSP variables and show new results proving that the physical mechanism responsible for LSPs is binarity. Namely, the LSP light changes are due to the presence of a dusty cloud orbiting the red giant together with the brown-dwarf companion and obscuring the star once per orbit. In this scenario, the low-mass companion is a former Jupiter-like planet that accreted a significant amount of mass from the envelope of its host star and grown into a brown dwarf.
Soberski Sebastian Planetarium i Obserwatorium Astronomiczne im. Mikołaja Kopernika w Grudziądzu Plakat/Poster Sebastian Soberski Astronomia Online Podczas pandemii COVID-19 popularyzacja astronomii w Planetarium i Obserwatorium Astronomicznym w Grudziądzu odbywała się z zdalny sposób. W ramach akcji online przeprowadzono kilkadziesiąt wykładów popularnonaukowych - transmisje na kanałach społecznościowych YouTube: @Planetarium2000; Facebook: @UraniaPA, @zgptma, @Planetarium.Grudziadz. Ponadto przeprowadzono online liczne warsztaty astronomiczne oraz skoordynowano akcję spotkań (platforma Zoom) oddziałów PTMA z różnych części Polski. W ramach działalności online przeprowadzono również XLVII Ogólnopolskie Młodzieżowe Seminarium Astronomiczno-Astronautyczne im. Profesora Roberta Głębockiego.
Ortuño-Macías José Nicolaus Copernicus Astronomical Center of PAS Plakat/Poster José Ortuño-Macías, Krzysztof Nalewajko Kinetic simulations of instabilities in cylindrical magnetized jets Relativistic jets are efficient sources of non-thermal radiation observed most prominently in the blazar class of active galaxies. They are thought to be highly magnetized collimated flows with an important contribution of toroidal magnetic fields (B_phi) prone to the current-driven instabilities (CDI). We investigate the development of the CDI in cylindrical jets by means of 3D kinetic numerical simulations in electron-positron pair plasma, starting from a range of initial configurations that bridge between the gas-pressure supported B_phi first studied by Alves et al. (2018, PhRvL, 121, 245101), and the axial magnetic field (B_z) supported B_phi first studied by Davelaar et al. (2020, ApJ, 836, L31). In the gas pressure supported case, we investigate the effect of the radial profile of toroidal magnetic field B_phi(r) on the maximum energy achieved by particles in the non-thermal high-energy distribution tail. For the flat profiles of B_phi(r), we demonstate for the first time the emergence of local CDI modes outside the central core. In the B_z supported case, we investigate the importance of magnetic reconnection with non-ideal electric field components for particle acceleration.
Nouri Fatemeh CFT PAN Wykład/Talk Fatemeh Nouri NUMERICAL STUDY OF ACCRETION OF THE MAGNETIZED NEUTRINO-COOLED TORUS ON A ROTATING BLACK HOLE Neutrino-cooled accretion flow around a black hole, produced by a compact binary merger, is a promising scenario for jet formation and magnetic-driven winds to explain short duration gamma ray bursts central engine and kilonovas based on GW170817 gravitational wave observation. Magnetorotational turbulence and Blandford-Znajek mechanism are expected to play key roles in the thermal equilibrium of the disk (balancing neutrino cooling) and in driving accretion and creating jets. Using the code HARM-COOL, developed in our group based on the open-source HARM GRMHD scheme, we study the magnetically-driven evolution of an accretion disk with realistic equation of state in the fixed curved space-time background. We identify the effects of the neutrino cooling and the magnetic field, paying particular attention to the dynamical, thermal and composition evolution of the disk and outflows.
Bicz Kamil Uniwersytet Wrocławski Plakat/Poster Kamil Bicz, Małgorzata Pietras, Robert Falewicz Modeling starspots on low mass star V374 Peg observed by TESS Quasi-periodic modulations of the stellar light curve may result from dark spots crossing the visible stellar disc. Since the release of the first TESS sector the possibility of examining such quasi-periodic modulations by assumed dark spots has increased. Thanks to this observations we tried to detect starspot coverage of low mass stars with visible variability of their luminosity. Using the light curves from TESS satellite and the new, BASSMAN package to fit spot models of different complexities, will constructed starspots distribution on individual stars. These models will then be tested to reveal a connection between the starspots and the stellar flares, in order to provide insight into the overall stellar magnetic field. Here we present results of modeling of starspots on V374 Peg with our new tool and compare the results with the previous reconstructions of the spatial distribution.
Dziadura Karolina Instytut Obserwatorium Astronomiczne, Uniwersytet im. Adama Mickiewicza w Poznaniu Wykład/Talk Karolina Dziadura, Dagmara Oszkiewicz, Przemysław Bartczak Asteroid astrometry with Gaia: searching for new Yarkovsky objects The Yarkovsky effect is a thermal process that changes spin axes during the time (da/dt) caused by the reradiation of a Sun energy. The effect is really small (~ 10^-4 au/My for a 1km object) and therefore difficult to measure (Greenberg et al. (2020). First-time the effect was proposed by Yarkovsky in 1901 and then popularized by Öpik in the 1950s. However, the first direct detection was only made in 2003 thanks to radar observations. Nowadays there are over a hundred detections for NEAs and only a few for Main-Belt objects. The main goal of this study is to improve an asteroid orbit using GAIA DR2 astrometry. The ESA Gaia mission was claimed to provide extremely precise astrometry of asteroids. Gaia observations were expected to lead to new Yarkovsky detections. We found a reliable detection of the Yarkovsky effect with a signal-to-noise ratio (SNR) greater than 3 for 21 asteroids. Moreover, we present a comparison of our results to the literature (if available) and expected values estimated using physical and orbital parameters of studied objects. Furthermore, we detected strong da/dt =  -200.0 +- 1.37  for an active asteroid 3200 Phaethon. This high da/dt value could be a result of a mass loss from Phaethon activity.
Itrich Dominika ESO Wykład/Talk D. Itrich, L. Testi, G. Beccari, C. Manara, Th. Preibisch, A. McLeod, M. Petr-Gotzens The complex image of star formation in Trumpler 14 with MUSE Nearby star-forming regions, like Orion, Taurus, or Lupus, are well studied thanks to their proximity. However, they reflect similar environmental conditions. While this can help us understand star formation in our neighbourhood, it may not be representative for the global picture of star formation in our Galaxy. Trumpler 14 is a young, 1-3 Myr (Hur et al., 2012) cluster in Carina Nebula complex. Carina Nebula is one of the largest and most massive star-forming region located in the inner Galaxy, ~2.3 kpc from the Sun (Smith 2006). Carina region was observed in far-infrared (e.g. Preibisch et al. 2012), near-infrared (e.g. Zeidler et all. 2016), optical (e.g. Beccari et all. 2015), and X-rays (e.g. CCCP: Chandra Carina Complex Project; Townsley et al. 2011). However, previous spectroscopical studies focused mostly on massive and bright stars, with only recently published survey with more that 1000 stars with masses down to ~1Msun (Gaia-ESO Survey, Damiani et al. 2017). Large number of massive OB stars in Carina complex heavily impact the local environment and the processes of star and planet formation. The aim of this work is to understand the impact of the violent conditions into the early star evolution with MUSE observations of the Trumpler 14 cluster in Carina Nebula. MUSE, as an Integral Field Spectrograph, allowed us to obtain the most complete sample of ~2000 star spectra in optical wavelengths in the region to date. The presence of many emission lines allows to study accretion in this region in a comprehensive manner. Combined with spectral classification and use of standard color-magnitude diagrams gives us a deep insight into the image of star formation in the violent conditions.
Hocdé Vincent Nicolaus Copernicus Astronomical Center Plakat/Poster Vincent Hocdé Mid-infrared circumstellar emission of the long-period Cepheid l Carinae resolved with VLTI/MATISSE The nature of circumstellar envelopes (CSEs) around Cepheids is a matter of ongoing debate. The physical origin of their infrared (IR) excess could be shown to either be made up of a shell of ionized gas, a dust envelope, or a combination of both. This study is aimed at constraining the geometry and the IR excess of the environment of the bright long-period Cepheid l Car (P=35.5 days) at mid-IR wavelengths in order to understand its physical nature. We first used photometric observations in various bands and Spitzer Space Telescope spectroscopy to constrain the IR excess of l Car. Then we analyzed the VLTI/MATISSE measurements at a specific phase of observation in order to determine the flux contribution as well as the size and shape of the environment of the star in the L band. We report the first detection in the L band of a centro-symmetric extended emission around l Car, of about 1.7 Rstar in full width at half maximum (FWHM), producing an excess of about 7.0% in this band. In the N band, there is no clear evidence for dust emission from VLTI/MATISSE correlated flux and Spitzer data. On the other side, the modeled shell of ionized gas implies a more compact CSE (1.13+/-0.02 Rstar) that is also fainter (IR excess of 1% in the L band). While the compact CSE of l Car is likely to be of a gaseous nature, the tested model of a shell of ionized gas is not able to simultaneously reproduce the IR excess and the interferometric observations. Further Galactic Cepheid observations with VLTI/MATISSE are necessary for determining the properties of CSEs, which may also depend on both the pulsation period and the evolutionary state of the stars.
Hełminiak Krzysztof CAMK PAN Wykład/Talk Hełminiak K. G., Moharana A., Pawar T., Marcadon F., Ratajczak M., Konacki M. TESS photometry of "creme de la creme" of Eclipsing Binaries Since 2011 we have been conducting an extensive spectroscopic survey (CREME) of detached eclipsing binaries (DEBs), and obtaining precise radial velocity (RV) data for hundreds of DEBs. The main goal was to identify and properly characterize new cases of poorly-studied or astrophysically interesting stars (e.g. low mass dwarfs, PMS, giants, pulsators, multiples, etc...). For most of them (currently ~240) we also gathered 2-minute cadence time series photometry from TESS through GI programs. Thanks to the superb data sets we are able to derive the values of fundamental stellar parameters (e.g. absolute masses, radii, temperatures) with a very high relative precision of 0.2-2%. To date we have identified for example ~40 DEBs with low-mass stars, 15 with (sub)giants, ~10 with pulsators of various kinds, ~80 multiples, or 5 with PMS components, as well as a number of exoplanet and BD candidates associated with eclipsing binaries.
Hellwing Wojciech Centrum Fizyki Teoretycznej PAN Wykład/Talk Wojciech Hellwing Caught in the cosmic web: Environmental effect on halo and galaxy properties Using a set of high-resolution simulations we study the statistical correlation of dark matter halo properties with the large-scale environment. We consider halo populations split into four cosmic web (CW) elements: voids, walls, filaments, and nodes. For the first time we present a study of CW effects for halos covering six decades in mass: 108- 1014h-1 M⊙ . We find that the fraction of halos living in various web components is a strong function of mass, with the majority of M >1012h-1 M⊙ halos living in filaments and nodes. Low mass halos are more equitably distributed in filaments, walls, and voids. For halo density profiles and formation times we find a universal mass threshold of Mt h∼6 ×1010h-1 M⊙ below which these properties vary with environment. Here, filament halos have the steepest concentration-mass relation, walls are close to the overall mean, and void halos have the flattest relation. This amounts to c200 for filament and void halos that are, respectively, 14% higher and 7% lower than the mean at M =2 ×108h-1 M⊙ . We find double power-law fits that very well describe c (M ) for the four environments in the whole probed mass range. A complementary picture is found for the average formation times, with the mass-formation time relations following trends shown for the concentrations: the nodes halos being the oldest and void halo the youngest. The CW environmental effect is much weaker when studying the halo spin and shapes. The trend with halo mass is reversed: the small halos with M <1010h-1 M⊙ seem to be unaffected by the CW environment. Some weak trends are visible for more massive void and wall halos, which, on average, are characterized by lower spin and higher triaxiality parameters. We extend the above presentation with the newest result from our Cosmic Web galaxy population analysis.
Hamed Mahmoud Narodowe Centrum Badań Jądrowych (NCBJ) Wykład/Talk Hamed M., Małek K. Dust attenuation in ALMA-detected Ultra Dusty Star-Forming galaxies up to z = 4 Despite its low contribution to the total mass of the interstellar medium (ISM), dust plays a crucial role in the evolution of galaxies, and it has the biggest impact on the spectral energy distribution. The affluence of infrared and radio detections of millions of galaxies in the COSMOS field, provided by powerful instruments such as Herschel and ALMA, has allowed us to study the cold dust in galaxies and its variation over a wide range of redshift. The key to reproduce the total spectral energy distributions of galaxies is the assumption of a dust attenuation law which accounts for the behavior and the imprints of the dust. However, different studies have shown that a single law cannot fully model dust in a large sample of galaxies. This non-universality of attenuation laws should be considered in order to accurately account for dust, and therefore in determining the physical properties of galaxies. In this work, we study different attenuation laws in a large sample of ALMA-detected galaxies in the COSMOS field. We probe the resulting variation of the key physical properties of these galaxies such as the star formation rate, the stellar mass and the dust to stellar mass ratio. We also investigate the dust temperatures in the ISM and spatial extent of the dust continuum and the implication that it might have on the attenuation curve. We find that various attenuation curves must be used in order to reproduce the UV spectrum. Although these curves are not redshift-dependent, they are correlated to the relative spatial distribution to the stellar population of the heavily dust-obscured galaxies, and we find a dependence of attenuation laws on the cold dust emission temperatures constrained by ALMA.
gupta suhani Centrum Fizyki Teoretycznej Polish Akademii Nauk Wykład/Talk Suhani Gupta, Wojciech Hellwing, Maciej Bilicki and Jorge Enrique García-Farieta Universality of Halo mass function in ΛCDM and modified gravity cosmologies Large-scale structures in the Universe evolve under the influence of cosmic expansion and gravity. An important statistic in this context is the halo mass function, which measures the abundance of large-scale structures across epochs. Halo mass function is a sensitive probe of growth of cosmic structures, expansion history of the universe and nature of gravity and hence, constraining mass function can help us constrain cosmological parameters from observational data and effectively test GR on large-scales. Because of the self-similar nature of hierarchical structure formation, mass function in the standard cosmological model, ΛCDM, can be expressed as a universal function across redshifts. This can ease the complications involved in the study of non-linear growth and evolution of structures. We used a set of N-body simulations to formulate the halo mass function of two modified gravity models: f(R) and nDGP. We compared our results with ΛCDM predictions and found a systematic scale-dependent abundance which is a function of both redshift and cosmology. We also noticed that we can expect the same universality in mass function for modified gravity cosmologies. This shows that the self-similar nature of hierarchical structure formation is preserved in the case of modified gravity models. We have therefore used this nature of universality to develop a generic mass function for modified gravity models without the need to re-run expensive and time-consuming modified gravity N-body simulations. This will allow us to model non-linear structure formation in modified gravity cosmologies and forecast constraints on the fifth force.
Godłowski Włodzimierz Instytut Fizyki Uniwersytet Opolski Wykład/Talk W. Godłowski, J. Popiela, M. Biernacka, K. Bajan, Z-H. Zhu, E. Panko, P. Pajowska A construction of luminosity function for sample 6168 galaxy clusters The main idea of our project is constructing the luminosity function of galaxy clusters. This important astrophysical problem (Lin & Kirshner 1996) was analyzed many times for individual objects as a galaxy or a radio galaxy. However, because of lack of appropriate data the problem of constructing luminosity function for galaxy clusters was rather negligent till now. Even where the authors noted that they investigated luminosity function for galaxy clusters, in fact they analyzed luminosity function for galaxies belonging to clusters, not total brightness of the clusters. It is the reason that we decided to construct the luminosity function of total brightness of galaxy cluster which was performed by counting brightness of galaxies belonging to 6168 clusters from Panko-Flin Catalogue. We found that luminosity function for galaxy clusters is significantly different than obtained for optical galaxies, as well as for radio galaxies. In the talk, we will present notions that will enable us to construct the function. Then, we will discuss the obtained results, especially the dependence of the function on BM type of the cluster. The implication of our results for theory of formation of galaxies and their structures will be discussed as well.
Garcia-Farieta Jorge Enrique Center for Theoretical Physics CFT PAN Wykład/Talk Jorge Garcia-Farieta, Wojciech Hellwing, Suhani Gupta, Maciej Bilicki Discerning clustering effects of Modified Gravity cosmologies with large-scale redshift space distortions Modifications of the theory of gravity arise as an extension of General Relativity (GR) in an attempt to both explore new extra degrees of freedom of a phenomenological gravity theory and hopefully better describe cosmological observations. The effects of modifications of gravity are naturally imprinted in the distribution of large scale structures, and clustering analysis stands out as an important probe of the underlying cosmological model. A specific feature suitable to test gravity models is redshift-space distortions (RSD), which induce anisotropy in the observationally derived two point statistics of the cosmic tracers. We make use of large state-of-the-art N-body simulations to measure and model the two-point statistics of a variety of models, which include f(R) gravity and the normal branch of the Dvali-Gabadadze-Porrati (nDGP) braneworld. In terms of the clustering analysis, we find that the statistical significance of these signals largely diminishes due to a strong degeneracy between MG-enhanced clustering and modified tracer bias, therefore, we consider the relative clustering ratios as a statistics less bias-dependent. The clustering ratios foster noticeable differences between MG and GR models, such departures could be measured for the linear distortion parameter if non-linear effects at intermediate scales are correctly modeled. We also find that the selection of an optimal tracer sample depends on a particular statistics and gravity model to be considered. Finally, our results indicate that the clustering ratios give great promise to search for signatures of MG in the large-scale structure.
Figueira Miguel National Centre For Nuclear Research Plakat/Poster Miguel Figueira, Agnieszka Pollo, Katarzyna Małek The VIMOS Public Extragalactic Redshift Survey Calibration of SFR Indicators at z ~ 0.7 Having an accurate estimation of the Star Formation Rate (SFR) is crucial to understand the formation and evolution of galaxies over cosmic time. To go one step further from SDSS (z100Myr) may be problematic and can be difficult to remove properly. On the other side of the spectrum, the mid-IR 8um band tracing the emission of Polycyclic Aromatic Hydrocarbons around massive stars is also a good tracer of SFR but shows a different stellar contamination compared to other surveys. The luminosity at 24um is a good tracer of SFR in the redshift range studied in this paper, as expected, since it is a good tracer of total infrared luminosity up to z~1.3. The Hb line is a good tool to estimate the SFR even if Ha is not available. Nonetheless, the main line used as a SFR tracer, after Ha, is [OII] despite being more attenuated and being metallicity dependent. Interestingly and contrary to SDSS, a metallicity correction applied to the [OII] luminosity is not necessary to derive a good estimation of the SFR. We finally test the ability of the [OIII] line in estimating the SFR due to future surveys with the JWST. Even though it gives a rough estimation of the SFR, this line is found to be the worst calibrator at z~0.7, as already found in previous studies from the local Universe.
Drozda Paweł Center for Theoretical Physics PAS Plakat/Poster Paweł Drozda, Wojciech Hellwing, Maciej Bilicki Angular clustering in standard and modified gravity One of the key issues in testing gravity on large scales is identifying the observables where it may deviate from the standard theory - General Relativity, in the context of gravitational collapse structure formation scenario. Galaxy clustering statistics has been a standard tool for model testing in cosmology for more than 4 decades. In this work we investigate the angular clustering of galaxies and halos in standard and modified gravity models. We test various redshift ranges and target selection functions, in order to search and highlight data samples that could yield a strong gravity model testing properties. We report that such signals can be identified in carefully selected angular clustering samples, yielding a potential to use the current and upcoming fotometric Big Data for precise cosmological model tests.
James Bestin Centrum Fizyki Teoretycznej PAN Plakat/Poster Bestin James, Agnieszka Janiuk Variablity properties of jets from accreting black holes using GRMHD simulations Astrophysical black hole sources usually show variable accretion flows. These sources are found at different mass scales from the cores of active galactic nuclei, e.g. in radio loud objects such as blazars to gamma ray bursts. Both the gamma-ray bursts and blazars often have a relativistic jet pointing towards or at a small angle from our line of sight. In such sources, the variability of the inflow can be transmitted to the properties of outflows. It is also possible that these two kinds of sources share similar jet physics. Observational studies have shown correlations between the observed jet variability time-scales and Lorentz factor of the emitted jet. Motivated by these observational properties, we investigate the relation between the central engine and the variability properties of the jet outflows by means of numerical GR MHD simulations. We perform axisymmetric simulations of the evolution of a central engine composed of a magnetized torus around a Kerr black hole that results in the launching of a non-uniform jet. We probe the jet energetics at some chosen points along the jet direction and we measure the jet time variability at these specific regions.
Dąbrowski Bartosz Uniwersytet Warmińsko-Mazurski w Olsztynie Plakat/Poster DĄBROWSKI B., MIKUŁA, K., FLISEK P., VOCKS Ch., ZHANG P. , MAGDALENIC J., MOROSAN D., KRANKOWSKI A., ZUCCA P., MANN G., FROŃ A. Multi-instrumental observations of type III solar radio event registered by LOFAR on 22 August 2017 We hereby present the interferometric LOFAR observations of the solar radio event on 22 August 2017, during which the type III radio bursts have been detected. Solar radio image and dynamic spectra were recorded in the 10 – 90 MHz frequency band. Additionally to LOFAR observations, the data recorded by instruments onboard the Solar Dynamics Observatory (SDO) in the EUV spectral range, GOES and RHESSI in X-ray spectral range complement observations in the radio field. Our study shows that the LOFAR observations, in combination with observations at other wavelengths can give better understanding of the physical processes responsible for type III solar radio events generations.
Czart Krzysztof Urania - Postępy Astronomii Wykład/Talk Krzysztof Czart Wizyty astronomów w szkołach - podsumowanie i dalsze plany W 2019 roku wystartował projekt pod nazwą "Wizyty astronomów w szkołach" realizowany przez Polskie Towarzystwo Astronomiczne. Wzbudził olbrzymie zainteresowanie wśród szkół - o przyjazd astronoma na spotkanie z uczniami i nauczycielami zaaplikowało ponad 1800 placówek szkolnych. Zaprezentowane zostanie podsumowanie dotychczasowego przebiegu projektu oraz potencjalne możliwości na przyszłość.
Curyło Małgorzata Uniwersytet Warszawski, Obserwatorium Astronomiczne Wykład/Talk Małgorzata Curyło, Tomasz Bulik Predictions for LISA and PTA based on SHARK galaxy simulations Massive black holes, with masses ranging from tens of thousands to billions of solar masses are undeniably intertwined with their galactic hosts. There are a number of empirical relations linking central black holes with their galactic environment on both large and small scales, including bulge luminosities, stellar velocity dispersion or halo mass just to mention a few. Unfortunately, we are still unable to explain such relations in a detailed and consistent way and thus the origin, properties and evolution of massive black holes and galaxies themselves remain as open questions. In the talk we will present our analysis of a set of populations of massive black hole binaries generated in the recent semi-analytic model of galaxy evolution (SHARK). We focus on studying gravitational wave emission produced by these inspiraling binaries in terms of their detectability in LISA (Laser Interferometer Space Antenna) and PTA (Pulsar Timing Array) band covering nHz - mHz frequencies. The key advantage of SHARK is that it provides a way to explore a number of distinct models of black hole and galaxy evolution processes within a consistent framework and it was also successfully tested against EM observational data. Together with the number and character of complementary LISA and PTA detections it might help putting more rigorous constraints on our understanding of the birth and co-evolution of galaxies and massive black holes.
Cui Zijia University of Szczecin Wykład/Talk Zijia Cui, John C. B. Papaloizou, Ewa Szuszkiewicz On the importance of wave planet interactions for the migration of two super-Earths embedded in a protoplanetary disk We investigate a repulsion mechanism between two low-mass planets migrating in a gaseous protoplanetary disk, which at some point of the orbital evolution, is able to change their convergent migration to divergent migration. This mechanism invokes density waves emitted by one planet transferring angular momentum to the coorbital region of the other and then to the other planet itself through processes such as the horseshoe drag. By formulating simple analytical estimates, two conditions are derived for a planet to be effectively repelled. One is that it forms a partial gap in the disk and another is that this should not be so deep that there is not enough material for angular momentum exchange with the planet to take place. Using full two-dimensional hydrodynamical simulations we obtain divergent migration of two super-Earths embedded in protoplanetary disk as a result of repulsion between two planets and verify these conditions. Our results indicate that if the conditions in the disk favor the repulsion between two planets due to wave planet interactions, than we expect to observe either planet pairs with their period ratios greater, often only slightly greater, than resonant values or possibly no commensurabilities at all.
Cieciuch Filip Uniwersytet Warszawski Plakat/Poster Filip Cieciuch, Miljenko Čemeljić Star-disk magnetospheric interaction with non-dipolar stellar field In our study we investigate non-dipolar geometries of stellar magnetic field. We perform resistive and viscous magneto-hydrodynamical simulations of a star-disk system and compare the results for the dipole, quadrupole and octupole stellar magnetic fields.
Bzowski Maciej Centrum Badań Kosmicznych PAN Wykład/Talk M. Bzowski, M. Strumik, I. Kowalska-Leszczyńska, M.A. Kubiak, R. Wawrzaszek, P. Orleański GLObal solar Wind Structure (GLOWS) – investigating how solar wind varies with heliolatitude GLOWS (GLObal solar Wind Structure) is one of experiments on a NASA mission IMAP (Interstellar Mapping and Acceleration Probe), scheduled for launch into a Lissajous orbit around the Lagrange point L1 in 2025. The objective of GLOWS is to investigate the global heliolatitude structure of the solar wind and its evolution during the solar cycle. Additionally, GLOWS investigates the distribution of interstellar neutral hydrogen (ISN H) and the solar radiation pressure acting on ISN H. The objectives of GLOWS are accomplished by observation of the heliospheric hydrogen backscatter glow (the helioglow). The helioglow is created by resonant excitation of ISN H atoms within several au from the Sun by the intense solar electromagnetic radiation in the Lyman-α waveband 121.567 nm. The H atoms move in this region collisionless and thus immediately after excitation of the photons from the Sun, they re-emit them in random directions. Those re-emitted photons form the helioglow. The intensity of the helioglow observed at ∼1 au varies across the sky, dependent on the location of the observer; it is on the order of 200–1000 Rayleigh. GLOWS scans a 75° small circle in the sky, centered at a point offset by 4° from the Sun towards lower ecliptic longitudes. The diameter of the field of view of the instrument is ∼4° FWHM. After a day of observations, the spin axis of IMAP is redirected to maintain the 4° offset from Sun’s center, and the strip of the sky observed by GLOWS accordingly shifts in the sky. A product of daily observations is a lightcurve of the helioglow intensity, collected from the scanning circle and composed of registered counts of the instrument, accumulated in bins organized by spin angle of the spacecraft. The modulation of the lightcurve depends on one hand on the structure of the solar wind, and on the other hand on the location around the Sun from which the observations are taken. The set of observations collected during a prolonged time enables determining the latitude structure of the solar wind. The GLOWS detector is a non-imaging single-pixel Lyman-α photometer, effectively a photon counting instrument. It is conceptually based on the TWINS/LaD photometer originally designed to observe the terrestrial exospheric resonant Lyman-α glow. The instrument includes a collimator with a baffle, a spectral filter, and a channeltron (CEM) detector. They are connected to the electronics block, responsible for collecting the event pulses and binning them for downlinking to the ground. The instrument is designed and assembled in the Space Research Centre PAS (CBK PAN). GLOWS is sensitive to radiation within a ~2.5 nm band around the hydrogen Lyman-α wavelength. In addition to the heliospheric backscatter glow, it observes bright EUV stars from almost entire sky. Each star is observed twice per year. Thus, the mission is an opportunity for photometric studies of bright EUV stars on a time scale of ~5 years.
Bukowiecka Nikola CBK PAN Plakat/Poster Tomasz Zajkowski, Nikola Bukowiecka Polskie Towarzystwo Astrobiologiczne Polskie Towarzystwo Astrobiologiczne powstało w 2020 roku z inicjatywy polskich naukowców zajmujących się zagadnieniami związanymi z Astrobiologią. Celem Polskiego Towarzystwa Astrobiologicznego jest popieranie i inicjowanie aktywności pozwalających na rozwój astrobiologii i nauk pokrewnych, ich popularyzacja oraz integracja środowiska naukowego zainteresowanego tematyką astrobiologii w celu nawiązania współpracy nad projektami badawczymi. Nasze inicjatywy: Budujemy stronę na której znajdują się opisy badaczy oraz różnych działów astrobiologii. Zbieramy pomysły na inicjatywy edukacyjne i naukowe, pomagamy merytorycznie w festiwalach i zajęciach szkolnych, budujemy wystawy w centrach edukacyjnych, nagrywamy wywiady z astrobiologami, organizujemy panele dyskusyjne w tematach astrobiologicznych, organizujemy polską astrobiologiczną konferencje naukowe. Prowadzimy konto na Facebook, YouTube, LinkedIn, Twitter i TikTok. Zapraszamy do współpracy i zachęcamy do kontaktu przez formularz na stronie
Bielewicz Marcin National Centre for Nuclear Research / Join Institut for Nuclear Research Plakat/Poster Marcin Bielewicz, Lukasz Swiderski, Elzbieta Strugalska-Gola, Maciej Rybczynski, Zbigniew Wlodarczyk, Pawel Kankiewicz, Kamil Wojcik Muon astrophysics with the MCORD detector. The MPD (Multi-Purpose Detector) complex is the main component of the NICA (New Ion Collider fAcility) being built at the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The experiments conducted at MPD are to complement the research carried out in CERN laboratories. To increase the functionality of MPD, it was proposed to supplement it with an additional muon trigger system. This trigger will be used to calibrate and test other MPD sub-detectors with cosmic ray particles while the accelerator is not producing the experimental beam. Additionally, the trigger can be used as a Veto detector to reject cosmic rays background during experiments. A group of Polish scientists from the NICA-PL Consortium was invited to design and construct it. It was proposed to surround the MPD detector with an additional cylinder-shaped cosmic ray detector called MCORD (MPD COsmic Ray Detector). The MCORD will be based on long (1.6 m) plastic scintillators with silicon photomultiplier (SiPM) for light reading and an FPGA electronics for the analysis of the obtained signals. The MCORD detector was designed also to be used for astrophysical observations of extended air showers (EAS), especially for central part of it. It will enable the registration of multi-muon events. Due to its design, it enables the analysis of signals from any direction in relation to the zenith and horizon. This feature makes it a unique tool of this type in the world. The potential goals of these observations may be to try to explain the GZK-cutoff problem by trying to identify the sources of extremely high energy primary particles.
Bielewicz Paweł National Centre for Nuclear Research Plakat/Poster Paweł Bielewicz Studies of statistical properties of the Planck cosmic microwave background maps Studies of the cosmic microwave background are today one of the most important pillars of observational cosmology. They provide information not only on the initial conditions of the Universe but also on scales comparable to the horizon of the observable Universe. That gives a unique opportunity to pose important questions about very fundamental assumptions made in the standard cosmological model such as statistical isotropy and Gaussianity of the initial fluctuations. I will present those studies paying special attention to the results obtained recently using the state-of-the-art data from the Planck satellite.
Iwanek Patryk Astronomical Observatory, University of Warsaw Wykład/Talk Patryk Iwanek Multiwavelength study of Miras variability Pulsating stars have been known for over 400 years (since the discovery of periodic variability of o Ceti made by David Fabricius in 1596), yet their nature still leaves many unanswered questions. Thanks to both the rapidly evolving domain of observational astronomy and the great technological progress over past decades, it is nowadays possible to observe the sky at a wide range of wavelengths. Such a synoptic approach allows studies and in-depth analyses of the nature of stars at every evolutionary stage. We comprehensively study the variability of Miras in the Large Magellanic Cloud (LMC) by simultaneously analysing light curves in 14 bands in the range of 0.5 to 24 microns. We model densely covered, 20-years-long I-band light curves for over 1600 Miras, collected by The Optical Gravitational Lensing Experiment (OGLE). We fit these models to other optical/near-infrared/mid-infrared data collected by surveys that include VMC, WISE, and Spitzer to derive the variability amplitude ratio and phase-lag between bands as a function of wavelength. We show that the variability amplitude ratio declines with increasing wavelength, while the phase-lag between bands increases slightly with increasing wavelength. We analyze spectral energy distributions (SEDs) for 140 Miras, and based on synthetic light curves we provide Period-Luminosity Relations (PLRs) in 42 bands from existing and future sky surveys.
Karska Agata Uniwersytet Mikołaja Kopernika w Toruniu Wykład/Talk Agata Karska Outer Galaxy as a laboratory to study star formation across environments Star formation is ubiquitous in the Galaxy, but the physical and chemical conditions in star-forming sites might differ as a function of galactocentric radius. Due to the negative metallicity gradient, efficiency of gas cooling and dust shielding decreases in more distant regions. A lower interstellar radiation field and a decrease in cosmic-ray fluxes lead to a decrease in the gas heating and ultimately cause lower gas and dust temperatures in the outer Galaxy. The balance between these processes sets the physical conditions of the gas and dust, and likely affects star-formation rates and efficiencies. Thus, systematic surveys of star-forming regions in the outer Galaxy offer a unique opportunity to study the impact of the environment on star formation, and may bridge the gaps between the galactic and extragalactic star formation studies. In this talk, I will present recent results concerning identification of new star-forming regions in the outer Galaxy and their spectroscopy from near-infrared to submillimeter wavelengths obtained by the MA-LAB team at NCU in Toruń.
Nicewicz Janusz Młodzieżowe Obserwatorium Astronomiczne w Niepołomicach Wykład/Talk Janusz Nicewicz Nowe oblicze MOA Po trwającej prawie dwa lata przebudowie, oddano do użytku nowoczesny budynek Młodzieżowego Obserwatorium Astronomicznego w Niepołomicach. Przedstawiamy nową formę MOA i prowadzonych w nim zajęć.
Mikołajczyk Przemysław Instytut Astronomiczny, Uniwersytet Wrocławski Wykład/Talk Mikołajczyk P., Niemczura E., Kotysz K., Różański T. Mercury-manganese stars in the observations of TESS satellite Mercury-manganese (HgMn) stars have spectral types from B7 to B9 and luminosity classes III-V. They are classified by a strong line of Hg II at 398.39 nm and several lines of Mn II visible in the blue part of the spectrum. Abundance anomalies found in HgMn stars are due to atomic diffusion processes, which are very sensitive to mixing motions. Hence, it is not surprising that HgMn stars are slow rotators (projected rotation velocities less than about 75 km/s) and often dwell in binary systems. It is assumed that HgMn stars are non-magnetic chemically peculiar stars, however weak magnetic fields have been detected for some of them (e.g. Mathys and Hubrig 1995). In addition, periodic variability was discovered in the spectra of some HgMn stars, which may indicate inhomogeneous distribution of chemical elements on the surface and indirectly the presence of magnetic fields. However, investigations of the photometric variability of HgMn stars are still unexpectedly rare considering available data, both ground-based and satellite. Here we present the results of TESS photometry analysis for more than 100 known HgMn stars. Most stars in our sample appear to be variables, both known and new-found ones. Binarity, rotational modulation and internal pulsations are discussed as possible causes of variability.
Ngan Le Nicolaus Copernicus University in Toruń Plakat/Poster N. Le, A. Karska, C. Fischer, M. Kaźmierczak-Barthel, A. Mirocha, R. Klein, M. Sewiło, L. E. Kristensen, W. Fischer SOFIA/FIFI-LS Spectroscopy of Gy 3-7 cluster in the outer Galaxy Star formation is ubiquitous in the Galaxy, but the physical and chemical conditions in star-forming sites might differ as a function of Galactocentric radius. For example, due to the negative metallicity gradient, the efficiency of gas cooling and dust shielding is expected to decrease in the outer Galaxy. Here, we present the SOFIA/FIFI-LS mapping observations toward the Gy 3-7 cluster in the Canis Major star-forming region covering highly excited CO lines from J=14-13 up to 30-29, [CII] at 158 μm, and [OI] at 63 and 145 μm. The CO rotational temperature of ~300 K toward two dense cores is similar to other Galactic star-forming regions of similar masses. On the other hand, the ratio of total line emission in CO versus [O I] is comparable to star-forming regions in the Magellanic Clouds. Thus, Gy 3-7 is a suitable target to quantify the impact of low metallicity on star formation.
Narendra Aditya Jagiellonian University Plakat/Poster Maria Giovanna Dainotti, Malgorzata Bogdan, Aditya Narendra, Spencer James Gibson, Blazej Miasojedow, Ioannis Liodakis, Predicting the redshift of Gamma-Ray loud AGNs using machine learning AGNs are very powerful galaxies characterized by extremely bright emissions coming out from their central massive black holes. Knowing the redshifts of AGNs provides us an opportunity to determine their distance to investigate important astrophysical problems such as the evolution of the early stars, their formation along with the structure of early galaxies. The redshift determination is challenging, because it requires detailed follow-up of multiwavelength observations, often involving various astronomical facilities. Here, we employ machine learning algorithms to estimate redshifts from the observed γ-ray properties and photometric data of γ-ray loud AGN from the Fourth Fermi-LAT Catalog. The prediction is obtained with the Superlearner algorithm, using LASSO selected set of predictors. We obtain a tight correlation, with a Pearson Correlation Coefficient of 71.3% between the inferred and the observed redshifts, an average ∆znorm= 11.6×10−4. We stress that notwithstanding the small sample ofγ-ray loud AGNs, we obtain a reliable predictive model using Superlearner, which is an ensemble of several machine learning models.
Nanni Ambra NCBJ Wykład/Talk Nanni, A.; Burgarella, D.; Theulé, P.; Côté, B.; Hirashita, H. The metal and dust build-up in the Universe: constraints from Lyman-Break galaxies at the epoch of reionisation The chemical enrichment of galaxies is regulated by several physical processes: stellar birth and death, dust growth and destruction, galactic inflows and outflows. Understanding the interplay of such processes is essential in order to study the rise of metals and dust in the Universe, and to interpret the available and future observations of space- and ground-based telescopes operating at infrared and sub-millimeter wavelengths (e.g. Spitzer; ALMA; JWST). In this talk, I will present the results of a recent investigation focused on low-metallicity galaxies, and specifically, Lyman-Break galaxies at the epoch of reionisation and local dwarf galaxies, which are considered to be the local counterparts of Lyman-Break galaxies. I will show how the comparison between model predictions and observations allows us to identify the most relevant physical processes driving dust evolution in these systems, and how the information of local galaxies can be employed to interpret the observations of Lyman-Break galaxies at 5<z<10. We find that a fast enrichment in metals and dust from Type II supernovae followed by dust removal through galactic outflow is required to reproduce the observations, while destruction of dust by supernovae shocks has a limited efficiency. Dust growth in the interstellar medium is not necessary in order to reproduce the observations of the galaxies under study, possibly because of the low metallicity of their interstellar medium.
Nakoneczny Szymon Narodowe Centrum Badań Jądrowych Wykład/Talk S. J. Nakoneczny, M. Bilicki, A. Pollo, et al. Integrated Sachs-Wolfe effect (ISW) with Low Frequency Array (LOFAR) Dark energy (DE) is one of the biggest mysteries in our current understanding of the Universe. It is believed to cause the accelerated expansion of the Universe, but its nature remains mysterious. One of the observables which allows us to directly probe the DE is the Integrated Sachs-Wolfe effect (ISW). It imprints a change of energy in the photons of the cosmic microwave background (CMB) due to travel through evolving gravitational potentials in the expanding large-scale structure of the Universe. Observational studies of the effect require access to large cosmic structures, and it is detectable only on scales larger than ~10 degrees. In my talk, I will present intermediate results of detecting the ISW effect in the Low Frequency Array (LOFAR) survey, in view of constraining the equation of state for DE. The LOFAR radio survey provides observations of star forming galaxies (SFGs) and active galactic nuclei (AGNs). Our work is based on correlations of the large scale structure from the most recent 2nd Data Release of the LOFAR Two-metre Sky Survey (LOTSS), with CMB lensing and temperature maps from the Planck telescope. The current results are promising, and will be a part of the set of cosmological papers released together with other LOTSS DR2 analyses.
Naddaf Mohamad Center for Theoretical Physics PAS Plakat/Poster Mohammad-Hassan Naddaf, Bozena Czerny Dynamical Picture of Broad Line Region in FRADO Model We studied the 3-D version of the physically motivated model of Broad Line Region proposed by Czerny & Hryniewicz (2011). The model is based on the radiation pressure acting on dust at the surface layers of accretion disk. Using realistic description of the dust opacity we investigated the dynamics of dusty clouds under the influence of radiation coming from the entire disk. We show that the radiation pressure is strong enough to launch outflows (mostly failed) from the disk surface. The dynamics strongly depend on the Eddington ratio of the source and also dust-to-gas ratio. Cloud dynamics thus determines the 3-D geometry of the BLR.
Moharana Ayush Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences Plakat/Poster A. Moharana, K.G. Hełminiak, F. Marcadon, T. Pawar, M. Konacki Evolution and dynamics of stars in Tight Triple Systems Tight Triple Systems (TTS) have stars in a hierarchical configuration with a third star orbiting the inner binary with a period of fewer than 1000 days. Such systems are a hub of various dynamical interactions and are important for understanding the formation and evolution of stars in multiple systems. Having a detached eclipsing binary (DEB) as one of its components allows us to obtain precise stellar and orbital parameters of these systems. Various recent discoveries have been due to space-based photometry from Kepler and TESS. We present the accurate stellar and orbital parameters of TTS using TESS photometry, radial velocities from high-resolution spectroscopy, and eclipse timing variations from Solaris photometry. Using these accurate parameters we determine the evolutionary states of the stars and the dynamic interactions possible in this system.
Mobeen Muhammad Zain CAMK PAN Plakat/Poster Muhammad Zain Mobeen, Tomasz Kaminski, Alexis Matter, Markus Wittkowski, Claudia Paladini Mid-IR Environment of the Stellar Merger Remnant V838 Mon We study the structure of V838 Mon in the L band using the MATISSE instrument at the VLTI. Geometrical modelling of the squared visibilites and closure phases suggests an elongated structure with a position angle of ~-40 degrees, which is in agreement with observations in other bands. We also find the star in V838 Mon to be unresolved in the L band. Our observations seem to support the idea that V838 Mon is surrounded by a stable disk structure, as opposed to a transient dust feature.
Miszuda Amadeusz Instytut Astronomiczny, Uniwersytet Wrocławski Wykład/Talk Amadeusz Miszuda, P. A. Kołaczek-Szymański, Wojciech Szewczuk, Jadwiga Daszyńska-Daszkiewicz Evolutionary and seismic modeling of the delta Sct pulsator in a binary system AB Cas AB Cassiopeiae is a short-period, double-lined eclipsing binary consisting of components with masses of 2.01Ms and 0.37Ms. The primary star is a δ Scuti variable with the dominant radial mode. We present an in-depth analysis of all TESS data, uvby Stromgren light curves and available spectroscopic observations. In order to find the model that describes the past evolution and current observational status of the system, we construct binary evolution MESA models that reproduce the masses, radii and the position on the HR diagram of both components. The main goal of our studies is to demonstrate how the binary evolution affects the present stage and pulsational properties of δ Scuti stars. Therefore, in the next step, we compute nonadiabatic pulsational models to account for the instability in the whole range of the observed frequencies. Finally, we construct complex seismic models that fit, both, the frequency and the amplitude of the bolometric flux variations of the dominant radial mode. Such models constraint, in particular, the efficiency of convection in the outer layers of δ Scuti stars.
Misra Arpita Jagiellonian University Plakat/Poster Arpita Misra, Marek Jamrozy, Urszula Pajdosz-Śmierciak​ Low Frequency Observations Of Peculiar Radio Galaxies Galaxies display a myriad range of shapes and sizes. Among them are galaxies that are highly luminous at radio wavelengths. These radio galaxies have a striking feature of producing collimated jets from kiloparsec to megaparsec scale. They harbour supermassive black hole at their centre that power the relativistic particles and magnetic field producing radio jets. Such galaxies are mostly divided according to Fanroff and Riley classification depending upon their radio power and morphology. However, nowadays with modern highly resolved deep sky surveys more radio galaxies with uncommon morphology such as S-, X- and Z-shape are discovered. Radio galaxies with such twisted jets underlie a complex and dynamic mechanism taking place at their core whose study is crucial for an in depth analysis of galaxy evolution. With many theories explaining the cause behind these peculiar structures, there is less evidence in support of either of them. We intend to probe the distorted jet/lobe morphology in order to understand the physical conditions at the centre of such host galaxies and therefore we present here new 610 MHz data of a sample of S-shaped sources from dedicated low frequency Giant Metrewave Radio Telescope observations.
Małek Katarzyna National Centre for Nuclear Research Wykład/Talk Katarzyna Ewa Malek New directions in multi-wavelengths astrophysics: using radio data to uncover properties of star-forming galaxies in young Universe Understanding how galaxies evolve and how form their stars through cosmic time is one of the main topics in modern astrophysics. Nowadays we have far-infrared and radio surveys which detect emission from millions of regular star-forming galaxies at the epoch of cosmic noon and beyond. The combination of those unique data with optical and near infrared surveys creates an opportunity to study star formation processes in the young Universe on a wide scale. During my talk, I am going to focus on radio emission as one of the indicators of star-formation activity in galaxies and as an important component in the broadband spectral energy modelling process. I am going to discuss the newest results obtained from the joint project of the Herschel Extragalactic Legacy Project (HELP) and the International Low Frequency Array (LOFAR) survey.
Kępa Anna Centrum Badań Kosmicznych PAN Wykład/Talk Anna Kępa, Barbara Sylwester, Marek Siarkowski, Janusz Sylwester Zastosowanie metody ewolucji różnicowej do analizy widm rentgenowskich Słońca. Analiza widm rentgenowskich rozbłysków słonecznych pozwala wyznaczyć temperaturę, miarę emisji oraz obfitość pierwiastków, które dają wkład do strumieni w obserwowanych liniach widmowych. W prezentacji przedstawione zostanie nowe podejście do analizy widm rentgenowskich wykorzystujące metodę ewolucji różnicowej. W podejściu tym skład chemiczny emitującej rentgenowsko plazmy wyznacza się równocześnie z rozkładem tzw. różniczkowej miary emisji (differential emission measure: DEM). Metoda została zastosowana do analizy widm rentgenowskich zarejestrowanych za pomocą spektrometru RESIK. Pokazane zostaną testy metody i wyniki analizy widm dla jednego z rozbłysków klasy M1.9.
Lisiecki Krzysztof Instytut Astronomii Uniwersytetu Mikołaja Kopernika Plakat/Poster Krzysztof Lisiecki, Katarzyna Małek, Małgorzata Siudek, Agnieszka Pollo Red nuggets - hunting for untouched survivors from the early Universe In order to understand our Universe, how it was formed and how it transforms now, we trace galaxies at different evolution stages, study the amount of stars formed at different galaxy types and other main physical properties as a function of time. While we can practically easily detect and analyse sources at low-redshift, we face strong barriers at high-redshift due to resolution and detection limit. So far, our observational facilities have been nearly blind when looking back in time to an era when most stars are expected to have formed. Now, we finally have an opportunity to see those objects due to the technical progress of astronomical instruments. About a decade ago, astronomers discovered a population of compact massive galaxies - red nuggets, which evolve unaltered in the life of the Universe allowing us to have insight into the primordial Universe. While most of red nuggets merged with other galaxies over cosmic time, a small number survived in an unchanged form. These unchanged red nuggets represent a unique laboratory to study how the first massive galaxies form and evolve. I will present the process of searching for the red nuggets in a sample of $sim$90k galaxies in Vimos Public Extragalactic Redshift Survey, a spectroscopic survey at redshift 0.5< z <1.5. I will discuss the ambiguity in the definition of the so-called compact galaxies and present the largest sample of the red nugget candidates at redshift z$sim$0.7. Finally, I am going to show the first results of the physical parameters of our unique sample of 26 red nuggets selected under the most conservative criteria.
Leśniewska Aleksandra Instytut Obserwatorium Astronomiczne, UAM Wykład/Talk Aleksandra Leśniewska, Michał Jerzy Michałowski Dust production scenarios in galaxies at z ~ 6 - 8.3 Dust production is a very important issue in galaxy evolution. Unfortunately, we are still unable to determine its formation mechanism. I will present the investigation of dust production in nine galaxies at redshift z > 6, for which dust emission has been detected. In recent years, more accurate measurements were made using the most powerful instruments, eg ALMA, which contributed to better estimates of luminosities and sizes, and thus to determine the masses of gas, dust and stars in the studied galaxies. We conclude that asymptotic giant branch (AGB) stars did not contribute to the dust formation significantly in these Early Universe galaxies, and that supernovae are unlikely to produce the bulk of the dust mass. I will also present the results of other research regarding dust formation such as AGN contribution, modelling and other.
Lai Eleonora Veronica Centrum Astronomiczne im. Mikołaja Kopernika PAN Wykład/Talk Eleonora Veronica Lai The effects of stellar wind on HMXBs spectral-timing properties: the case of Cygnus X-1 in its hard state. High mass X-ray binaries accrete via the stellar wind of their supermassive companion. The stellar wind does not appear as a smooth flow, but it shows strongly dense and highly perturbed regions or clumps. As these clumps pass our line of sight, part of the X-ray emission is absorbed, leading to dipping events in the X-ray light curve. We performed an analysis of the long XMM Newton monitoring of the black hole binary Cyg X-1/HDE 226868 during its hard state. This monitoring is part of the CHOCBOX (Cyg X-1 Hard state Observations of a Complete Binary Orbit in X-rays) campaign. In this talk, I will present the latest results on the effects of the stellar wind on the spectral-timing properties of Cyg X-1 for more than one and a half orbital periods. In particular, I will show how these properties change significantly as a function of the orbital phase, due to the orbital variability of wind absorption.
Kuligowska Elżbieta Obserwatorium Astronomiczne Uniwersytetu Jagiellońskiego Plakat/Poster Kuligowska, Elżbieta, Mirocha, Agnieszka Astrolabium – konkurs astronomiczny The National Astronomical Competition "Astrolabium" has been organized since 2013 by the Krakow Astronomical Observatory of the Jagiellonian University and its partner organizations. The aim is to promote science, especially astronomy and space research, among primary and secondary school students. The competition consists of two stages: the development of competition experiences and the knowledge test, carried out in the schools entered. The formula of the competition allows to acquire the skills of scientific work and conducting and developing experiments. In this presentation, we will briefly describe the competition and its challenges in recent years.
Kruszyńska Katarzyna Obserwatorium Astronomiczne Uniwersytetu Warszawskiego Wykład/Talk Katarzyna Kruszyńska, Ł. Wyrzykowski, P. Zieliński, I. Gezer, K. Rybicki, N. Ihanec Highlights of photometric microlensing with Gaia Science Alerts On the 19th of December 2013 Gaia Space Satellite was launched by European Space Agency. Its main goal is to measure proper motions and parallaxes of over 1 billion stars in Milky Way. However, ever since the first data has been acquired in 2014, Gaia has observed much more than that. Up to this day its alerting system of sudden change in brightness of observed sources AlertPipe has detected almost 17'000 transients. More than 300 of them have been classified as microlensing candidates from all over the sky, with Gaia16aye, Gaia18cbf, Gaia8dif, Gaia19bld and Gaia19dke among them. Microlensing events detected and observed by Gaia offer a possibility for registering not only photometric effect, but also its astrometric counterpart. This will provide additional data, that will help to break degeneracies for single source-single lens events, which might lead to mass measurements of lenses and, in particular, to discovering lensing black holes. We will present higlights form events found in the past years including results of ground-based follow-up campaigns with OPTICON network. We will show most interesting events and provide a quantitative summary of results obtained in recent years.
Kowalska-Leszczyńska Izabela Space Research Centre, PAS Wykład/Talk Izabela Kowalska-Leszczyńska, Marzena A. Kubiak, Maciej Bzowski The solar Lyman-α line – why is it so important in heliospheric studies? One of the most prominent lines in the UV part of the solar spectrum is the Lyman-α line. The center of the line corresponds to the wavelength λ=121.567 nm. The line profile has a characteristic 2-horned shape that is changing with solar cycle phase. Using direct measurements done by the SOHO/SUMER spectrometer (Lemaire et al. 2015), we developed a model that allows us to calculate the shape of the line depending on solar cycle phase (Kowalska-Leszczynska et al. 2018 and 2020). The Lyman-α line is important in heliosphere studies because it modifies the trajectories of the ISN H (interstellar neutral hydrogen) atoms due to resonant radiation pressure. Thus, it has a direct impact on the distribution of this gas inside the heliosphere and is responsible for the creation of the helioglow, which is the fluorescent emission of interstellar neutral H atoms within a few au from the Sun. The solar Lyman-α photons are absorbed and randomly re-emitted by ISN H atoms, which modifies the radiation pressure, and as a consequences – the distribution of the gas itself. We analyzed this problem and identified when and where this absorption should be included in the simulations of the ISN H distribution in space and of ISN H-related signals observed by various space missions.
Kowalczyk Krzysztof Centrum Nauki Kopernik Plakat/Poster Krzysztof Kowalczyk Prosto z nieba, czyli popularyzacja odkryć polskich astronomów w Planetarium Centrum Nauki Kopernik Cykl „Prosto z nieba” to niezwykłe, multimedialne pokazy w Planetarium Centrum Nauki Kopernik, połączone z rozmowami z wybitnymi specjalistami. Comiesięczne wykłady w cyklu, odbywające się w ramach projektu „SPINaj naukę”, przybliżają widzom w Planetarium i widzom online dokonania polskich astronomów.
Koprowski Maciej Uniwersytet Mikołaja Kopernika Plakat/Poster Maciej Koprowski, Agata Karska, Marta Sewi︎ło, Lars E. Kristensen, Hannah Calcutt, Konrad Grzesiak ALMA survey of molecular outflows in the Canis Major star forming region Star forming region CMa-l224 hosts ∼ 300 low- and intermediate-mass young stellar objects (YSOs) recently identified with Sptizer and Herschel surveys of the outer Galaxy. Near-infrared integral field spectroscopy revealed multiple H2 jets, which are characteristic of deeply-embedded protostars. Yet, high extinction toward the densest regions requires submillimeter spectroscopy to properly characterize protostellar ejections. In this poster we will present ALMA Band 6 observations toward 70 dense cores in the CMa-l224 region identified with the ’Herschel Infrared GALactic Plane Survey’. The ALMA spectral cubes at ∼220 GHz, covering a field of view of ~0.35 arcmin^2, reveal a spatial extent of 13CO 2-1 and C18O 2-1, as well as serendipitous detections of H2CO 3-2, N2D+ 3-2, SO 6-5, and CH3OH 5-4. We find the mean values of the bolometric temperatures and luminosities, as well as envelope masses, of 31.16 ± 0.95 K, 4.83 ± 0.99 L⊙ and 0.55 ± 0.12 M⊙, respectively. The envelope mass was found to be anti-correlating with the bolometric temperature, confirming Menv to be a good proxy for YSOs evolutionary stage. Investigating the detection rate of N2D+, we found that it decreases with Tbol. We determine masses and forces for 20 high-velocity 13CO J=2-1 outflows. Placing them on the outflow force/envelope mass plane, we found that our sample lies below the expected correlation, most likely due to 13CO data missing highest-velocity gas. Finally, we found that the single-dish 12CO data produces results consistent with interferometric observations but finds outflows with significantly larger areas, likely due to the much coarser resolution.
Kołaczek-Szymański Piotr Uniwersytet Wrocławski Plakat/Poster Piotr Kołaczek-Szymański, Andrzej Pigulski, Marcin Wrona, Milena Ratajczak Zmiany amplitud oraz częstotliwości oscylacji wzbudzanych pływowo Gwiazdy typu ,,heartbeat'' należą do grupy układów podwójnych o dużym mimośrodzie, w których odkształcenia pływowe oraz inne efekty bliskości prowadzą do powstania charakterystycznej krzywej blasku układu w pobliżu peryastronu, która przypomina elektrokardiogram. Ponadto, okresowo zmienne siły pływowe mogą prowadzić do wymuszenia danego modu oscylacji w gwieździe (ang. tidally-excited oscillations, TEO), który bez obecności drugiego składnika nie byłby widoczny, ze względu na jego tłumioną naturę. Z teoretycznego punktu widzenia, TEO powinny charakteryzować się częstotliwością będącą dokładnie całkowitą wielokrotnością częstotliwości orbitalnej oraz względnie stałą amplitudą, ze względu na fakt ciągłego wzbudzania z okresem orbitalnym. W swojej prezentacji chciałbym przedstawić rezultaty analizy zmian amplitud oraz częstości TEO w jednym z masywnych układów ,,heartbeat''.
Żołnowski Michał 6ROADS Ltd. Wykład/Talk Michał Żołnowski, Marcin Gędek, Rafał Reszelewski, Mikołaj Pieniowski Możliwości obserwacyjne prywatnej sieci teleskopów optycznych 6RODAS 6ROADS jest siecią ośmiu automatycznych teleskopów obserwujących zjawiska w Układzie Słonecznym. Jej działalność skupia się przede wszystkim na obserwacjach obiektów NEO oraz tzw. śmieci kosmicznych i sztucznych satelitów. Głównymi elementami sieci są teleskopy optyczne o średnicach od 0.25 do 0.4 metra wyposażone w wysokiej czułości kamery. W skład 6ROADS wchodzą obserwatoria w Polsce, Włoszech, Hiszpanii, Namibii, Chile, USA oraz Japonii. Każde z obserwatoriów posiada precyzyjną służbę czasu pozwalającą na dokładne określenie czasu rejestrowanego zjawiska. 6ROADS uczestniczy w wielu ważnych projektach pod auspicjami Europejskiej Agencji Kosmicznej, europejskiego konsorcjum EU SST oraz komercyjnej działalności dla operatorów satelitarnych. Prywatny charakter przedsięwzięcia pozwala na swobodne zarządzanie siecią oraz szybkie podejmowanie decyzji dotyczących planów obserwacyjnych. Dzięki sporemu doświadczeniu 6ROADS w ostatnich latach dokonało wielu ciekawych obserwacji naturalnych oraz sztucznych obiektów w sąsiedztwie Ziemi.

Lp. Nazwisko (Last name) Imię (First name) Instytucja/Affilation Abstrakt2 Rodzaj Abstrakt2 Autorzy Abstrakt2 Tytuł Abstrakt2 Treść
Armiński Andrzej Polskie Towarzystwo Miłośników Astronomii Plakat/Poster Andrzej Armiński Polskie obserwatorium Marina Sky w Hiszpanii Plakat przedstawia genezę, możliwości techniczne i sposób działania zrobotyzowanego obserwatorium astronomicznego w Nerpio w Hiszpanii (kod IAU Z06), dysponującego dwoma teleskopami o średnicy zwierciadeł 17 i 12.5 cali oraz przykłady wyników obserwacji.
Bzowski Maciej Centrum Badań Kosmicznych PAN Wykład/Talk Maciej Bzowski, Marzena Kubiak Warm Breeze from starboard bow in the heliosphere: its discovery and interpretation The Sun with its heliosphere is penetrating a warm, partly ionized cloud of interstellar gas. The neutral component of this cloud penetrates freely inside the heliosphere and is detected by spaceborne detectors, including in situ direct sampling by Interstellar Boundary Explorer (IBEX). The direct-sampling technique brings information on the temperature of the local interstellar medium in the Sun’s immediate neighborhood and on the Sun’s motion across the local cloud, which are the fundamental factors that shape the heliosphere. However, our analysis of measurements of interstellar neutral helium (ISN He) by the IBEX-Lo detector showed that in addition to the expected flux of the unperturbed interstellar helium wind, there exists another flow of neutral He, which was dubbed the Warm Breeze. We will discuss the evidence that led to the discovery of the Warm Breeze and present the interpretation of this flow as a product processes operating just beyond the heliopause. We will also present implications of these measurements for the physical state of local interstellar matter, including the ionization state and the vector of local magnetic field.
Curyło Małgorzata Uniwersytet Warszawski, Obserwatorium Astronomiczne Plakat/Poster Małgorzata Curyło, Timothy Pennucci Wideband timing of Parkes Pulsar Timing Array UWL data Pulsar timing array (PTA) experiments provide extraordinary means to study a wide range of physical phenomena across nearly all branches of physics and astronomy. In particular, analysis of variations in pulse times of arrival (ToAs) of millisecond pulsars can be used in searches for nHz gravitational waves generated by, e.g. supermassive black hole binary inspirals or cosmic strings. However, as such processes may have a very subtle effect on our measurements, an increase of the precision is a vital element of current PTA efforts. There are a number of possible improvements that can be applied to observational strategies, instrumentation and analysis techniques. In consideration of that, an ultra wideband receiver (UWL) has been installed in Parkes Observatory (Australia) in 2018, providing now nearly 3 years of 704 - 4032 MHz observations. In the talk we will present an additional improvement that we have been working on in Parkes, that is the first results of applying wideband timing methods (specifically Pulse Portraiture) to UWL datasets. These techniques aim to tackle new problems arising from large fractional bandwidths along with increasing the precision of ToA measurements and we show that they constitute a promising direction for current PTA developments.
Czart Krzysztof Urania - Postępy Astronomii Plakat/Poster Krzysztof Czart, Wieńczysław Bykowski, Rafał Grabiański, Piotr Majewski, Bogumił Radajewski, Małgorzata Radomska, Sebastian Soberski Urania TV czyli portal Uranii na YouTube Obecność portalu Uranii ( na YouTube przejawia się w postaci kilku różnych edukacyjnych serii wideo i podcastów radiowych. Poza głównymi filmami z serii Urania TV dostępne są też cykle "Urania w podróży", "Kosmiczne rozmowy", "Urania FM", "Niebo na dłoni". Wszystkie materiały dostępne są pod adresem
Iwanek Patryk Astronomical Observatory, University of Warsaw Plakat/Poster Patryk Iwanek The most accurate mid-infrared Period-Luminosity Relations for Miras Pulsating stars are excellent distance indicators in the nearby Universe, because they obey Period-Luminosity Relations (PLRs). We used densely covered, 20-years-long I-band light curves for 1663 Miras in the Large Magellanic Cloud (LMC), collected by The Optical Gravitational Lensing Experiment (OGLE), to create I-band light curve templates. Using these templates and mid-infrared observations from the Spitzer and WISE space telescopes (spanning a wavelength range from 3.4 to 22 microns), we measure the mean magnitudes for almost the full sample of Miras. We then construct PLRs in four Spitzer and four WISE bands. These PLRs allow measurements of the distance to individual Miras at the level of ~5%, and could be used for measuring distances in the Milky Way.
Leśniewska Aleksandra Instytut Obserwatorium Astronomiczne, UAM Plakat/Poster Aleksandra Leśniewska, M. J. Michałowski, P. Kamphuis, K. Dziadura, M. Baes, J. M. Castro Ceron, G. Gentile, J. Hjorth, L. K. Hunt, M. P. Koprowski, E. LeFloc’h, H. Miraghaei, A. Nicuesa Guelbenzu, D. Oszkiewicz, 
E. Palazzi, M. Polińska, J. Rasmussen, P. Schady, D. Watson The interstellar medium in the environment of the supernova-less long-duration GRB 111005A There exists two classes of gamma ray bursts (GRBs), which are distinguished by the duration of the prompt high-energy emission. Long GRBs, with durations larger than 2 s, are firmly associated with the explosions of massive stars, although in three instances, luminous supernovae (SNe) have not been detected, despite deep observations. The nature of these bursts is unclear. Our aim is to establish the properties of the interstellar medium (ISM) of the host galaxy of one of these events, GRB 111005A, in order to shed light on the nature of these peculiar objects. We used new HI line measurements and previously published optical integral field spectroscopy in order to analyze the environment in which the GRB was located. We studied the distribution of the host properties e.g. atomic gas mass, star formation rate (SFR), and kinematics. The host galaxy of GRB 111005A turned out to be characterized by regular largely symmetrical atomic gas, radio continuum distribution, and rotational patterns. This is different from the irregular ISM distributions seen in the hosts of long GRBs and type Ic SN.
Nanni Ambra NCBJ Plakat/Poster Nanni, A.; Groenewegen, M. A. T.; Aringer, B.; Rubele, S.; Bressan, A.; van Loon, J. Th; Goldman, S Estimating the gas and dust enrichment from carbon-rich stars in the Magellanic Clouds We present an investigation aimed to estimate the mass-loss and dust production rate and other properties of the carbon stars in the Magellanic Clouds (MCs). To achieve this goal we perform the spectral energy distribution (SED) fitting of the entire populations of carbon stars in the MCs over pre-calculated grids of spectra. The grids of spectra are computed as a function of the stellar parameters by consistently following the dust growth of different dust species, i.e. SiC and amorphous carbon, and the wind dynamics. Differently from the usual approach in the literature, our method allows to compute the dust production rates, gas-to-dust ratio, dust chemistry and expansion velocity of the outflow, and to estimate the mass-loss rates of carbon stars. The optical constants for amorphous carbon are selected on the basis of their ability to reproduce different observations in the infrared and optical bands of Gaia Data Release 2. An excess of extreme mass-losing carbon stars in the Large Magellanic Cloud (LMC) with low gas-to-dust ratios over the carbon stars in the Small Magellanic Cloud (SMC) is found. Typical gas-to-dust ratios is around 700 for the extreme stars in both galaxies, but the value can be down to approximately 160-200 and 100 for a few sources in the SMC and in the LMC, respectively. Such low values of the gas-to-dust ratios indicate that the process of dust condensation is particularly efficient around the reddest carbon stars in these galaxies. The extreme carbon stars in the LMC observed with the Atacama Large Millimeter Array (ALMA) and their wind speed are studied in detail. Our method is able to reproduce the SED as well as the expansion velocities of these sources. For the most dust-obscured star in this sample we estimate a large value of the mass-loss rate of ~6.3x10-5 M☉ yr-1. The method introduced will be useful to plan and interpret upcoming observations of evolved stars performed with ALMA and other facilities. For this purpose, the grids of spectra and dusty models employed for this analysis will be publicly available.
Panda Swayamtrupta Center for Theoretical Physics, Polish Academy of Sciences Wykład/Talk Swayamtrupta Panda The CaFe Project: Optical Fe II and Near-Infrared Ca II triplet emission in active galaxies - simulated EWs, the co-dependence Modelling the low ionization lines (LIL) in active galactic nuclei still faces problems in explaining the observed equivalent widths (EWs). I examine the optical Fe II and near-infrared Ca II triplet (CaT) emission strengths using the photoionization code CLOUDY. Using an incident continuum for I Zw 1 - a prototypical Type-1 narrow-line Seyfert galaxy, we can recover the line ratios for the optical Fe II (i.e. RFeII) and the NIR CaT (i.e. RCaT) in agreement with the observed estimates. Although, the pairs of (U, n) that reproduce the conforming line ratios, unfortunately, do not relate to agreeable line EWs. To reconcile this issue, I propose that the LIL region of the BLR cloud doesn't see the same continuum seen by a distant observer that is emanated from the accretion disk, rather it sees a filtered version of the original continuum. The assumption of the filtered continuum as the source of BLR irradiation recovers realistic EWs for LIL species. However, this study finds that to account for the adequate RFeII (Fe II/Hβ flux ratio) emission, the BLR needs to be selectively overabundant in iron. On the other hand, the RCaT (CaT/Hβ flux ratio) emission spans a broader range from solar to super-solar metallicities. In all these models the BLR cloud density is found to be consistent with our conclusions from prior works, i.e. n∼10^{12} per cc. An interesting result obtained here is the reduction in the value of the metallicity by up to a factor of 10 for the RFeII cases when the microturbulence is invoked, suggesting that microturbulence can act as an apparent metallicity controller for the Fe II. On the contrary, the RCaT cases are rather unaffected by the effect of microturbulence.
Prince Raj Center For Theoretical Physics, PAN, Warsaw, Poland Plakat/Poster Raj Prince Broadband study of BL Lac during flare of 2020: Spectral evolution and emergence of HBL component BL Lacertae (BL Lac) categorized as a source of high energy photon in the TeV catalog and considered as a possible source of astrophysical neutrinos. The source has shown the brightest X-ray flare ever detected from it. A detailed study can answer many puzzling questions related to multiband emission and fast variability often seen in this kind of source. We have performed the temporal and spectral analysis of the brightest flare. The variability is characterized by the fractional variability amplitude and the variability time. A broadband SED modeling is done to answer the possible physical mechanism responsible for broadband emission. We found that the source has crossed all its previous limits of flux and reached to a maximum ever seen from this source in optical and X-rays. In X-ray, the fractional variability is found to be above 100% (1.8397±0.0181) within a time span of a day. The fastest X-ray variability time is estimated as 11.28 hours within a matter of a day, which is seen first time in this source. The other multiband emissions are found to be highly correlated with X-ray within the one day of time lag. The broadband SED modeling requires two different location sites two explain the low and high flux state. A significant spectral change was observed in the optical-UV and X-ray spectrum which eventually leads to the result that the synchrotron peak is shifted towards the higher energy and BL Lac behaves like an HBL type source during the high state.
Rathour Rajeev Singh Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences Plakat/Poster Rajeev Singh Rathour and Radosław Smolec Candidate for period-doubling effect in Blazkho modulated RRc candidate from OGLE-IV survey Classical pulsators such as RR Lyrae stars are known to exhibit quasi-periodic modulation of pulsation amplitude and phase known as Blazhko effect. A century has passed after its discovery but its cause still remains to be a mystery. In recent years, another dynamical effect known as period-doubling was observationally established in Blazhko modulated fundamental mode RR Lyrae stars. In the light curves, it is manifested by alternating maxima over cycles and in the frequency domain as peaks at half-integer frequencies of the radial mode. So is there a connection between the Blazhko effect and the period-doubling phenomenon? Yes, quite intimately connected as current hydrodynamical models propose a 9:2 resonance between the fundamental mode and the 9th overtone mode as the cause of both phenomena: period-doubling and Blazhko modulation. May a similar mechanism operate in modulated first overtone stars? Here, we report a detection of period-doubling signature in the first overtone Blazhko RR Lyrae (RRc) star from the OGLE-IV survey of the Galactic bulge sample. The candidate has a pulsation period (P1O) of ∼0.254 d and a modulation period (PB) of ∼12.446 d. Successive pre-whitening analysis results in a frequency peak at half integer of the radial mode, indicating period doubling. However, it is a low amplitude signal to observe any manifestation directly in the light curve. We also present frequency analysis of Kepler observations of KIC 4484128, which is a well established modulated fundamental mode RR Lyrae star with period-doubling effect, to show the correspondence with our candidate.
Włodarczyk Ireneusz Polskie Towarzystwo Astronomiczne/Polskie Towarzystwo Miłośników Astronomii Plakat/Poster Ireneusz Wlodarczyk The dangerous asteroid (29075) 1950 DA We computed impact solutions of the potentially dangerous asteroid (29075) 1950 DA based on 768 optical observations from 1950 February 22.23014 to 2021 July 4.618248, and twelve radar observations from 2001 March 03 to 2012 May 01. We selected 770 observations. To compute the possible impact solution of the asteroid (29075) 1950 DA with the Earth, we used the OrbFit software with the JPL DE431 ephemerides, weighting and selecting observations according to the Near-Earth Objects Dynamic Site (NEODyS) (, two different error models, 4 and 17 additional massive asteroids, and the Yarkovsky effects. We searched for the possible impacts using the non-gravitational parameter A2, computed directly from observations. A2 is a non-gravitational transverse acceleration parameter. We have shown that the possible impact date is the same for different error models and additional perturbing massive asteroids. However, the probability of Earth's impact is most significant for four additional perturbing massive asteroids.
Wójtowicz Anna Obserwatorium Astronomiczne Uniwersytetu Jagiellońskiego Plakat/Poster Wójtowicz, A. ; Stawarz, Ł. ; Cheung, C. C. ; Ostorero, L. ; Kosmaczewski E.; Siemiginowska, A. On the Jet Production Efficiency in a Sample of the Youngest Radio Galaxies Here we discuss the sample of confirmed young radio galaxies with measured kinematic ages and nuclear X-ray fluxes. The analyzed targets are sufficiently young so that the currently observed luminosities of compact lobes and accretion disks correspond to exactly same episode of the AGN activity. For the targets, we analyze the available optical data, estimating the bolometric luminosities of the accretion disks $L_{rm bol}$, and the black hole masses; we also derive the minimum jet kinetic kinetic luminosities, $P_{rm j}$. With such, we investigate the distribution of our sample in the three-dimensional space of the accretion parameter $lambda_{rm Edd} equiv L_{rm bol}/L_{rm Edd}$, the nuclear X-ray luminosity $L_{rm X}$ considered here as a limit for the emission of the accretion disk coronae, and the jet power $P_{rm j}$. We find that (i) the accretion parameter $lambda_{rm Edd}$ in our sample is distributed within a narrow range from $lambda_{rm Edd} sim 0.01$ up to $sim 0.2$; (ii) the normalized jet power formally correlates with the accretion rate; (iii) the jet production efficiency $eta_{rm jet} equiv P_{rm j}/dot{M}_{rm acc} c^2$ spans a range from $eta_{rm jet} lesssim 10^{-3}$ up to $sim 0.2$ at maximum, which is below the level expected for magnetically arrested disks around maximally spinning black holes; and (iv) there is an interesting diversification in $eta_{rm jet}$ on the hardness--intensity diagram $L_{rm X}/L_{rm bol} - lambda_{rm Edd}$, with the jets being produced the most efficiently during the high/hard states, and suppressed during the soft states.
Wyrzykowski Lukasz Astronomical Observatory, University of Warsaw Plakat/Poster Łukasz Wyrzykowski, Paweł Zieliński, Mariusz Gromadzki, Krzysztof Rybicki, Monika Sitek OPTICON-RadioNET Pilot (ORP) and coordination of the european time-domain astronomy ORP ( is a consortium of 37 partners funded under European Comission's H2020 grant (2021-2024). Its main mission is to facilitate astronomical discoveries by providing research infrastructures in optical and radio. We will describe the Time-Domain astronomy work package lead by the University of Warsaw. We will present tools for homogenous photometric and spectroscopic data processing and multi-facility observations request as well as our plans for time-domain pilot projects in the multi-wavelength domain.

Lp. Nazwisko (Last name) Imię (First name) Instytucja/Affilation Abstrakt3 Rodzaj Abstrakt3 Autorzy Abstrakt3 Tytuł Abstrakt3 Treść
Iwanek Patryk Astronomical Observatory, University of Warsaw Plakat/Poster Patryk Iwanek 12 660 spotted stars towards the OGLE Galactic bulge fields We have discovered 12 660 spotted variable stars towards and inside the Galactic bulge from over two-decade-long Optical Gravitational Lensing Experiment (OGLE) data. We have proposed a new method of the individual object dereddening because, due to a strong and highly non-uniform extinction towards the Galactic bulge, standard dereddening methods and existing extinction maps fail for many stars. In effect, 11 812 stars were classified as giants and 848 as dwarfs. Well defined correlations between luminosity, variability amplitude and rotation period were found for the giants. Moreover, our two-band, high-cadence photometry has allowed us to find
 a clear correlation between the brightness variations and color variations of the stars. The division of stars into separate groups, 
based on this correlation, is clearly visible on the color-magnitude diagram (CMD).
Włodarczyk Ireneusz Polskie Towarzystwo Astronomiczne/Polskie Towarzystwo Miłośników Astronomii Plakat/Poster Ireneusz Wloarczyk The close encouters with the asteroid (1) Ceres We computed the close encounters of (1) Ceres with the first 3000 numbered Near-Earth Asteroids. We have shown that the mean distance between (1) Ceres and the Near-Earth Asteroids is 0.125 au. The corresponding value of velocity is 5.0 km/s.

Lp. Nazwisko (Last name) Imię (First name) Instytucja/Affilation Abstrakt4 Rodzaj Abstrakt4 Autorzy Abstrakt4 Tytuł  Abstrakt4 Treść
Włodarczyk Ireneusz Polskie Towarzystwo Astronomiczne/Polskie Towarzystwo Miłośników Astronomii Plakat/Poster Ireneusz Wlodarczyk The asteroid 2021 PH27 with the highest solar system precession rate We presented the orbit of 2021 PH27. According to the JPL NASA classification ($#$top), 2021 PH27 belongs to the Atira group asteroid. Their orbits are contained entirely within the orbit of the Earth (Q $<$ 0.983 au). Also known as an Interior Earth Object. As of 2021 August, 21 JPL NASA shows 26 Atira objects. The most recently discovered object, as of 2021 August 21, is 2021 PH27. It has a=0.4614 au, e=0.7903 and i=31.66 deg. Asteroid 2021 PH27 has the highest Solar System precession rate, as far. It is greater than the observed precession rate of Mercury, which is 574.1"/100 yrs.