Dwindling accretion of CVs at the turnaround of period minimum. The case of V498 Hya

by Gaghik Tovmassian (UNAM-Ensenada, Mexico)

Thursday 14 Dec 2023, 11:30 → 12:30 Europe/Rome

Sala Jappelli (Osservatorio Astronomico di Padova)

According to the standard evolutionary model of Cataclysmic Variables (CVs), it is predicted that nuclear burning in the donor star ceases when mass transfer erodes its mass to approximately 0.06 times the mass of the Sun. At this stage, the star's structure becomes dominated by electron degeneracy and becomes a brown dwarf. As a result, further reduction in mass causes the orbital period to increase.  As the evolution of CVs slows towards the period minimum and reverses towards longer periods, an accumulation of systems near the period minimum is expected.

The dedicated spectroscopic follow-up of CV candidates carried out by SDSS-V obtained nearly complete spectroscopy of
period-bounce candidate systems, which we use to derive a more stringent estimate of the space density of period bouncers, but the spike in numbers is not detected.

This study presents observations conducted using OSIRIS@GTC of a potential period bouncer candidate SDSS 0845555.06+033929.3, surveyed by the SDSS-V Milky Way Mapper program. We determine its orbital period through time series spectroscopy and demonstrate that it is yet another period bouncer.

 

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