-------------------------------------- | | | Biuletyn PTA nr 8 | | | -------------------------------------- Biuletyn informacyjny Zarzadu Glownego Polskiego Towarzystwa Astro- nomicznego (Adres kontaktowy: M. Ostrowski, pta@oa.uj.edu.pl , a w bardzo pilnych sprawach: mio@oa.uj.edu.pl ) ======================================================================= Spis tresci: I. Uwagi edytora Biuletynu II. Etat dla astronoma we Fromborku III. Osrodki astronomiczne w Polsce a. Zaklad Promieniowania Kosmicznego w Instytucie Fizyki w Lodzi b. Zaklad Fizyki Slonca CBK PAN we Wroclawiu IV. Nowinki naukowe ======================================================================= I. Uwagi edytora Biuletynu Poczynajac od obecnego numeru biuletynu rozpoczynamy prezentacje osrodkow astronomicznych w Polsce. Zwrocilem sie do dyrektorow/kierownikow wszystkich - o ktorych wiem - osrodkow, w ktorych prowadzi sie badania astronomiczne lub blisko zwiazane z astronomia. Prosze o informacje od grup zajmujacych sie taka tematyka, do ktorych moja prosba nie dotarla. Zebrana w punkcie IV masa nowinek naukowych nazbierala sie przez wakacje. Zamieszczam tu wprost kopie informacji odnoszacych sie do astronomii wybranych z Physics News Update. Gdyby ktos chcial otrzymywac pelna liste nowosci z tego zrodla, to znajdzie instukcje wpisania sie na liste wysylkowa na koncu dzisiejszych nowinek. Readktor Biuletynu nie prowadzi krytycznej oceny czy selekcji pojawiajacych sie nowosci. Niemniej niejednokrotnie napotyka sie na informacje o pracach co najmniej dyskusyjnych. Gdyby ktos mial ochote skomentowac niektore z tych nowinek - nie dluzej niz w 15 liniach tekstu - to chetnie takie komentarze zamieszcze. ======================================================================= II. Etat dla astronoma we Fromborku Muzeum Mikolaja Kopernika we Fromborku wciaz poszukuje astronoma, ktory zechcialby zamieszkac na terenie Obserwatorium i pracowac w dziale Planetarium i Obserwatorium Astronomiczne. Bardzo prosze o przekazanie mojej prosby do wszystkich czlonkow PTA: jesli ktos zna astronoma poszukujacego pracy w swoim zawodzie, bardzo prosze o skierowanie go do Fromborka. Andrzej S. Pilski skr. poczt. 6 14-530 Frombork e-mail (grzecznosciowo): oa@planetarium.olsztyn.pl ======================================================================= III. Osrodki astronomiczne w Polsce a. Zaklad Promieniowania Kosmicznego w Instytucie Fizyki w Lodzi Zaklad Promieniowania Kosmicznego, ul. Pomorska 149/153, Katedra Fizyki Doswiadczalnej, 90-236 Lodz, Uniwersytet Lodzki Poland * Kierownik Zakladu - Prof. dr hab. Maria Giller ================================================ * Pracownicy zajmujacy sie astrofizyka - 10. ================================================ Prof dr hab. Maria Giller (Badanie promieniowania kosmicznego (PK) najwyzszych energii - przyspieszanie PK w wietrze pulsara, propagacja w halo galaktycznym, wspolpraca w eksperymencie KASKADE i Auger); Dr Wlodzimierz Bednarek (Dyskretne zrodla promieniowania gamma i neutrin. Pochodzenie PK.); Dr Lech Kacperski (Badanie PK najwyzszych energii - wspolpraca w eksperymencie Auger), Dr Andrzej Maciolek-Niedzwiecki (Galaktyczne i pozagalaktyczne zrodla promieniowania rentgenowskiego - teoria i analiza danych.); Dr Wojciech Michalak (Przyspieszanie PK w wietrze pulsara. Obliczenia widm PK penetrujacych namagnesowany wiatr pulsara w Krabie.); Dr Dorota Sobczynska (Poszukiwanie zrodel promieniowania gamma - badanie promieniowania Cherenkova od kaskad fotonowych); Dr Zbigniew Szadkowski (Badanie PK najwyzszych energii - wspolpraca w eksperymencie Auger - budowa aparatury); Dr Wieslaw Tkaczyk (Propagacja w polach magnetycznych i oddzialywanie PK, udzial w eksperymentach Auger i SPHERA); Dr Tadeusz Wibig (Badanie skladu masowego PK w obszarze 10^15 eV (m.in. eksp. KASKADE), badanie PK powyzej 10^17eV); Dr Maria Zielinska (Halo magnetyczne wokol Galaktyki, jego powstanie i rozwoj oraz wplyw na tory czastek PK najwyzszych energii.) ========================= * Liczba doktorantow - 3. ========================= Mgr. Michal Lipski (Przyspieszania PK przez pulsary.); Mgr. Tadeusz Pytlos (Badanie skladu pierwotnego PK w zakresie energii 10^15-10^17 eV przy uzyciu danych pochodzacych z eksperymentu KASKADE.); Mgr. Andrzej Smialkowski (Pochodzenie i propagacja PK najwyzszych energii. Struktura i rozmiar halo galaktycznego oraz jego wplyw na propagacje PK.) ========================= * Publikacje w 1997 roku: 8 (recenzowane) + 18 (nierecenzowane). >From bednar@krysia.uni.lodz.pl Tue Sep 29 17:42:06 1998 ------------------------------------------------------------------------ ------------------------------------------------------------------------ b. Zaklad Fizyki Slonca CBK PAN we Wroclawiu Zaklad Fizyki Slonca CBK PAN Projekty eksperymentalne: INSTRUMENT: Fotometr rentgenowski RF-15I (na pokladzie Interball Tail Probe, zrealizowany we wspolpracy z IA AN Czech) dokonuje (pomyslnie od trzech lat) pomiarow calkowitego strumienia rentgenowskiego Slonca w zakresie 2keV-240keV. CEL NAUKOWY: Badanie struktury zmiennosci calkowitego promieniowania X Slonca w skalach czasu od sekund do dni ze szczegolnym uwzglednieniem rozblyskow INSTRUMENT: RESIK - Spektrometr Bragga z wypuklymi krysztalami (przygotowywany do umieszczenia na pokladzie satelity Koronas-F, przewidywany termin startu: 1999/2000). Prowadzony jest montaz lotnych podzespolow elektroniki przyrzadu RESIK. Aktualizowane jest oprogramowanie procesorow pokladowych. Tzw. testy end-to-end przewidywane sa pod koniec 1998 w laboratorium Rutherforda-Appletona, UK CEL NAUKOWY: Badanie skladu chemicznego plazmy w koronie Slonca poprzez analize widm X w zakresie 0.1 -0.6 nm INSTRUMENT: DIOGENESS - Skanujacy Spektrometr Bragga (rowniez na misje Koronas-F) Wyjustowano, z dokladnoscia do 10 sekund luku plaskie krysztaly Bragga w indywidualnych sekcjach spektrometru. Trwa kalibracja detektorow przy uzyciu zrodla radioaktywnego (Fe55). Aktualizowane jest oprogramowanie procesorow pokladowych. CEL NAUKOWY: Badanie ruchow goracej (T>5MK) plazmy w rozblyskach _______________________________________________________ Zagadnienia teoretyczne: * Badanie skladu chemicznego plazmy w koronie Slonca * Analiza wlasnosci fizycznych plazmy w strukturach koronalnych (w oparciu o dane uzyskane z pokladu japonskiego satelity Yohkoh). * Zastosowania dekonwolucji (problem odwrotny) w fizyce Slonca -Metody okreslania funkcji rozproszenia instrumentalnego (Point Spread Function, "slepe rozpoznanie" ) -Okreslanie rozkladow rozniczkowej miary emisji -Struktura przestrzenna koron gwiazowych -Metody maksymalnej entropii, maksymalnej wiarygodnosci Wykorzystywane dane obserwacyjne: Satelity: Yohkoh, przyrzady: SXT, HXT, BCS GOES - fotometry rentgenowskie SOHO - EIT TRACE ____________________________________ Sklad osobowy: samodzielni: Marek Siarkowski Barbara Sylwester Janusz Sylwester - kierownik badawczy: Szymon Gburek Anna Kepa Zbigniew Kordylewski - zca kierownika inzynierowie - lacznie 3.5 osoby prac. techniczni - 3 osoby obsluga - 1.5 osoby ______________________________________ Lokale: wlasny pawilon (300 m^2) na terenie IA UWr + 110m^2 = najmowanych od IA UWr Adres: ul. Kopernika 11 51-622 Wroclaw ______________________________________ Wyposazenie: komora prozniowa do testow aparatury, pracownia = elektroniczna, etc Komputeryzacja: LAN polaczony z siecia metropolitalna laczem FDDI serwer SunSparc20 64Mb serwer Linux PC Pentium 128 Mb serwer Linux PC Pentium 256 Mb Bardziej wyczerpujace dane zamieszczamy stopniowo na naszej stronie www. Zapraszam! +----------------------------+----------------------------+ | Janusz Sylwester | tel: (+4871) 3483238 | | Space Research Centre | fax: (+4871) 3729372 | | Polish Academy of Sciences | or: (+4871) 3729378 | | Solar Physics Division +----------------------------+ | ul. Kopernika 11 |e-mail: js@cbk.pan.wroc.pl | | 51-622 Wroclaw, Poland | www : www.cbk.pan.wroc.pl | +----------------------------+----------------------------+ ======================================================================= IV. Nowinki naukowe KAONS INSIDE SUPERNOVAS. K mesons (kaons) are exotic, short-lived particles of interest not just to high-energy physicists but also to astrophysicists since the behavior of K's inside dense nuclear matter can place severe constraints on the dynamics of supernova explosions and the stability of neutron stars. Recent experiments at the GSI lab in Darmstadt, Germany (Peter Senger, 011-49-6159- 712-652, p.senger@gsi.de) have looked for K's in violent collisions between gold nuclei (at a beam energy of 1 GeV/nucleon). In those collisions, the reaction zone is compressed to about 3 times normal nuclear density for a very short time, about 5 x 10^-23 sec. Then, this nuclear fireball explodes and the gold nuclei disintegrate. During the hot and dense phase, strange mesons---mostly positively charged kaons---are created. These emerge preferentially out of the plane of the collision; apparently the high density of the reaction zone offers the kaons nowhere to escape but up or down. The pattern of kaon trajectories indicates that the effective mass of the kaon is altered in the extreme nuclear environment, in line with other experiments. These data have been explained by the suggestion that anti-kaons "condense" at nuclear densities above 3 times normal nuclear matter density. As a consequence, one can predict that a star with a 1.5-2 solar-mass iron core will not subsequently be able to sustain itself as a neutron star following a supernova explosion but would instead collapse into a black hole. (Physical Review Letters, 24 Aug.) NEAREST EXTRA-SOLAR PLANET. The existence of a planet around the star Gliese 876, only 15 light years distant from Earth, was announced this week by planeteer Geoffrey Marcy of San Francisco State University at a meeting in Victoria, British Columbia. The star, whose presence is inferred not from direct observation but by the wobble it imparts to the star, has a mass about 1.6 that of Jupiter. Gliese itself only has a mass of about one third that of our sun, making it the lightest known star to have a planet. The planet circles the star every 61 days at a radius of one -fifth the Earth-Sun distance. The discovery was soon confirmed by other astronomers. (Science News, 27 June 1998.) Still other extra-solar planets (perhaps a half dozen) will be presented by several observing teams at a meeting a week from now in Santa Barbara. (Science NOW, 24 June 1998.) THE MOON WAS THE FIRST OBJECT OF PURE SCIENCE, according to Martin Gutzwiller of IBM (gutzwil@watson.ibm.com). The Babylonians (c1000 BC) recorded the comings and goings of the Moon arithmetically without understanding the geometry. The Greeks (c200 BC) went further; they viewed the solar system as sitting in an immense vacuum surrounded by the fixed stars. But even the clever Greeks knew nothing about the underlying physics of the solar system. This fell to Newton (1687) in the "Principia," and the 18th century mathematician/physicists such as Laplace. These thinkers proposed the principle of universal gravitation and tried to check it out on the complicated Moon-Earth-Sun system. The study of this oldest of three-body problems is the true subject of Gutzwiller's article in the April 1998 issue of Review of Modern Physics. In many physics problems, the dynamics of two interacting bodies (a planet and a star or two electrical charges, say) is easy. Add a third body and things get complicated, indeed chaotic, which is why Newton and his 18-century followers were largely stumped in their efforts to nail down the Earth-Sun-Moon dynamics. Gutzwiller compares the study of this problem with the history of particle physics: the amassing of cross sections, branching ratios and other particle properties (the kinds of things published in tables) corresponds to the "Babylonian phase," while the advent of the standard model represents the "Greek phase." The third, or Newtonian, age, in which the masses of the quarks and fundamental parameters such as the fine structure constant will be explained, has not yet arrived. (For a study of the 3-body problem with ions, see Update 372) NO END IN SIGHT FOR COSMIC RAY ENERGIES. Putting terrestrial accelerators to shame, nature has contrived to imbue some particles with energies greater than 10^20 electron volts. But these high-end cosmic ray events---only a mere handful have been recorded so far---would seem to be at odds with the idea that interactions with the cosmic microwave background act as a sort of universal brake, permitting energies not much above 10^19.6 eV (the so called Griesen-Zasepin-Kuz'min, or GZK, limit). It didn't help that for some time there was a relative scarcity of events in the energy range between 10^19.6 and 10^20 eV. But new data reported by the Akeno Giant Air Shower Array (AGASA) collaboration in Japan (Masahiro Takeda et al., mtakeda@icrr.u- tokyo.ac.jp) fills in this gap, strengthening the statistical argument that either the GZK cutoff is not working as planned or that some unexpected process is producing the highest-energy rays.In other words, there seems to be no limit to cosmic ray energy. (Takeda et al., Physical Review Letters, 10 August 1998.) A SUN-EARTH CONNECTION EVENT, in which a gust of plasma particles (a coronal mass ejection) detaches from the Sun and travels all the way to our planet, where it causes electromagnetic disturbances and atmospheric auroras, has been monitored from start to stop for the first time. The International Solar-Terrestrial Physics Observatory, a network of ground-based and satellite detectors, watched the drama play out over the period January 6-11, 1997. The absence then of notable surface features on the Sun, such as flares, reinforces the notion that coronal rather than surface activity is more important for determining near-Earth space storms. (Several articles in the July issue of Geophysical Research Letters.) THE INTERNATIONAL PHYSICS OLYMPIAD, the annual competition which sets tough problems to some of the best high school students in the world, was held this year in Iceland. As befits the fire-and-ice locale, some of the problems involved finding the pressure under an ice cap, determining the results of lava intrusions into icefields, and the motion of superluminal radio jets, which can be thought of as the astrophysical equivalent of lava flows. The national teams with the most number of gold medals were China (5), Russia (3), and Vietnam and Iran with one each. The U.S. team earned one silver medal (Andrew Lin, Wallingford, CT) and one bronze (Peter Onyisi, Exeter, NH). (See the upcoming issue of the Announcer, published by the American Association of Physics Teachers.) DO COSMIC RAYS COME FROM QUASARS? Cosmic ray particles, which crash into Earth's atmosphere setting up huge showers of particles detected on the ground, have mysterious origins. Looking at the five most energetic events ever recorded (energies above 10^20 eV), Glennys Farrar of NYU (farrar@physics.nyu.edu) and Peter Bierman of the Max Planck Institute for Radio Astronomy in Bonn have found that all the events are consistent with the cosmic rays having originated in radio-loud quasars with redshifts in the range 0.3-2.2, and propagating undeflected and unattenuated in energy through the intervening thousands of Mpc (Physical Review Letters, tentatively 19 October 1998). If the particles (conventionally assumed to be protons) are indeed coming from a great distance then how do they evade the Greisen-Zatsepin-Kuzmin (GZK) cutoff, according to which cosmic rays with energies above about 10^19.5 eV would be sapped of their energy through interactions with cosmic microwave background photons if they traveled much more than 20 Mpc (roughly 60 million light years)? Such interactions would typically produce pions and electron-positron pairs. Some speculate that the high-energy particles are not protons at all but some exotic new particle. One explanation is that energetic neutrinos make the long cosmic journey and then annihilate relatively near the Earth with massive dark-matter neutrinos to create the cosmic ray primary particle. Farrar herself is partial to the notion that the primary is the neutral S particle, an amalgam of three quarks and a gluino (one of the shadow particles associated with supersymmetry theory; see Updates 86 and 265). With a mass two or three times that of the proton, the S would not as readily produce pions in interactions with microwave photons, thus ensuring for itself a more robust passage through the cosmos. Thus the highest energy cosmic rays could be produced at cosmological distances but still survive the trip to Earth. (Physics Today, October 1998.) Future measurements determining whether the primary is a photon or hadron will help decide the question of whether the correlation between cosmic rays and quasars holds up. THE 25 GREATEST ASTRONOMICAL FINDINGS of all time, according to the editors of Astronomy magazine (October 1998) are as follows: the discovery of quasars (1963); the cosmic microwave background (1965-66); pulsars (1967); Galileo's observations of the phases of Venus, Jupiter's moons, and craters on the moon (c 1609); extrasolar planets (1992); supermassive black holes (early 1990s); Newton's Principia, formulating the mathematics of our heliocentric system (1687); the discovery of Uranus (1781); the first known asteroid (1801); discovery of Pluto (1930); Neptune (1846); spectroscopic proof that nebulae are gaseous in nature (1864); recognition of galaxies beyond our own (1923); the advent of radio astronomy (1931-32); studies of globular clusters help to map the Milky Way (1918); cometary explosion over Siberia (1908); an accurate measurement of the speed of light (1675); Southern Hemisphere celestial objects cataloged (1834-38); Cepheid-variable period-luminosity relationship worked out (1912); Copernicus' De Revolutionibus sets forth the heliocentric system (1543); Laplace's theory on how the solar system formed (1796); a transit of Venus suggests Venus has an atmosphere (1761); the Hertzsprung-Russell diagram for understanding how stars age (1913); scheme for classifying star types (1890); the use of parallax for finding a star's distance from Earth (1838). THE EXTRASOLAR PLANET PARADE continues with the discovery of two new planets with unique features. As before, astronomers Geoffrey Marcy (San Francisco State) and Paul Butler (Anglo-Australian Observatory) have inferred the presence of the planets from their observed influence on the companion star. One of the new objects orbits its star (HD187123) in a mere three days in an orbit 9 times closer than Mercury's around our sun. The other new planet has a very Earth-like orbit of 437 days around star HD21027. This comes as a reassurance to those who were beginning to wonder whether Earth was an anomaly; all previously discovered extrasolar planets have had orbits much smaller or much larger than Earth's. (San Francisco State University press release, 23 September 1998.) MILKY WAY IN THE LABORATORY? A plasma with a spiral-shaped pattern of particle density, similar to that of the Milky Way galaxy, has been created stably in the laboratory, supporting the possibility that fluid dynamics effects rather than gravitational ones may be responsible for our home galaxy's structure. Injecting a hot argon plasma (rotating at supersonic speeds) into a cold, stationary argon gas, researchers in Japan (Takashi Ikehata,Ibariki University, ikehata@ee.ibaraki.ac.jp) observed a spiral-armed structure (with low-density halos of charged particles) that persisted for as long as they kept rotating the plasma. The vortices that typically appear in such hot plasmas became spirals because of the outward "centrifugal" forces introduced by the rotation. Curiously, the spiral structure was not observed to form in the absence of the stationary gas, suggesting that the fluid dynamics interactions between the gas and plasma are central to the spiral formation process. This experiment intensifies the fascinating (and still undecided) question of whether similar interactions occur between hot, bright stars (corresponding to the plasma) and gas clouds (analogous to the stationary gas) to form spiral galaxies. (Ikehata et al., Physical Review Letters, 31 August 1998.) A TRAVEL GUIDE TO EUROPEAN SCIENCE would proceed from London to Paris to Moscow to Amsterdam. These cities, according to Institute of Scientific Information (ISI), were responsible for the greatest number of published scientific papers during the period 1994-1996. If one ranks by per-capita output the order of top European cities becomes Cambridge, Oxford, and then Geneva/Lausanne. In the field of physics the leaders in producing papers are Moscow, Paris, Geneva, St. Petersburg, and Warsaw. Narrowing further to condensed matter physics, the order begins with two Russian cities, Moscow and St. Petersburg, followed by Paris, Berlin, and Stuttgart. (Science, 21 August 1998.) THE FIRST SNAPSHOT OF AN EXTRASOLAR PLANET? The existence of extrasolar planets around several stars has been inferred from the wobble in the stars' emissions, but the planets themselves have not been seen amid the glare of the parent stars. Now, the Hubble Space Telescope has taken a picture of an object (named TMR-1C) that might, depending on how the data is interpreted, be either a brown dwarf star or a protoplanet (perhaps with a mass several times that of Jupiter). The object, about 450 light years away and glowing in infrared light, was glimpsed at all because it has apparently been ejected from a nearby binary-star system, and therefore stands apart from any stellar brilliance. This and the object's youth (it might be only 100,000 years old) might redirect thinking on how gas giant planets form. According to NASA scientist Edward Weiler, "If the planet interpretation stands up to the careful scrutiny of future observations, it could turn out to be the most important discovery by Hubble in its 8-year history." (NASA press release, 28 May 1998.) A PULSAR WITH A MAGNETIC FIELD OF 8 x 10^14 GAUSS has been studied with the Rossi X Ray Telescope (RXTE). Referred to as a soft gamma-ray repeater (SGR1806-20) since it is a source of recurring bursts of low-energy gamma-rays (whereas gamma ray bursters don't emit higher energy gammas and don't repeat), this neutron star rotates with a period of about 7.4 seconds. The size of the magnetic field, 100 times larger than that of ordinary radio pulsars, is deduced from the rotation period and the slowdown of that rotation. Such a highly magnetized neutron star has been called a "magnetar." The huge field (the largest magnetic field ever measured) puts the star's surface under great stress. According to one theory, the observed high energy bursts of radiation come about when the neutron star's crust cracks open. (C. Kouveliotou et al., Nature, 21 May 1998.) PHYSICS NEWS UPDATE subscription reminder: To put yourself on our distribution list automatically, send a message to listserv@aip.org (not to physnews@aip.org) and specify either "add physnews" or delete physnews" to subscribe or unsubscribe.