Contributed Talk - Splinter Stellar

Thursday, 24 September 2020, 14:59   (virtual room M)

Investigating the effect of a circumbinary disk on Main Sequence star abundance patterns

Olga Lebiga
Institut für Physik und Astronomie, Universität Potsdam

Hot subdwarf B stars are core helium-burning stars formed by stripping the envelope of a low-mass star through mass transfer during the red-giant phase. Some of them are found in binary systems with cool main-sequence companions indicating a former episode of stable mass transfer. There are indications that during this process a circumbinary (CB) disk might be formed, which is very difficult to observe directly because of its short lifetime. In this talk, I will propose a method to find indirect evidence of the existence of a CB disk by using the depletion effect in the MS companion star сaused by accretion from the CB disk. I will describe the connection between the presence of the disk and the depletion of heavy metals in the companion star atmosphere and show preliminary results of MESA simulations predicting the strength of the effect for MS stars of different mass.