Izabela Kowalska-Leszczyńska

Space Research Centre

Session X: Poster session

Thursday 14th September 2023 12:00 – 13:00

abstract:
The Sun, along with the heliosphere, moves through a partially ionized interstellar medium. While charged particles flow around the heliosphere along the lines of the magnetic field, neutrals freely enter its interior. Thanks to this, we can directly capture particles from outside the heliosphere and use them to study the conditions prevailing in the interstellar medium. Neutral particles traveling toward the Sun are attracted to it by gravitational force but also repelled by the force associated with radiation pressure. Hydrogen atoms are the most vulnerable to this effect because they are the lightest. During periods of high solar activity, these atoms can even be pushed away from the Sun. In the case of helium, the influence of radiation pressure has been neglected until now. Is it justified? The answer, as in many other cases, is: it depends…
I will show when radiation pressure acting on the helium can be neglected and when it has to be taken into account and why.