Astronomy & Astrophysics Seminar: Stable Hydrogen Burning on Accreting White Dwarfs
Tal Kerklies, TAU
A fundamental question of stellar evolution is: can a white dwarf (WD) grow in mass by accretion from a binary companion? This is linked to the big question of Type Ia supernova progenitors. Accretion onto a WD usually leads to nova outbursts and mass loss, so the WD may even lose mass. It is possible, however, to reach conditions of steady burning, where the accreted mass is burnt relatively quietly, that is, without mass loss. Indeed, numerical models show that there is a range of accretion rates for which the energy release is not strong enough to trigger mass ejection. However, a controversy arises among numerical evolution modelers, those who claim mild non-ejecting outbursts and those who claim steady burning, namely, burning accreted material at precisely the rate of accretion. The purpose of our study was to shed light on the "steady burning" scenario by an analytical approach: 1. Find whether there is a unique solution to the problem. 2. Find the range of accretion rates to which steady burning corresponds. 3. Conclude whether steady burning can be achieved in reality (and what would be the observational implications).
Seminar Organizer: Dr. Iair Arcavi