Companions to sdB binaries−degenerate or non-degenerate?
- Resource Type
- Original Paper
- Authors
- Maxted, Pierre F.L.; Morales-Rueda, Luisa; Marsh, Tom R.
- Source
- Astrophysics and Space Science: An International Journal of Astronomy, Astrophysics and Space Science. June 2004 291(3-4):307-314
- Subject
- binaries:
close
spectroscopic
subdwarfs
- Language
- English
- ISSN
- 0004-640X
1572-946X
We report the results of an on-going programme to collect lightcurves for EHB binaries with orbital periods P ≲ 1 d. Degenerate and non-degenerate companions are clearly distinguished by the presence or absence of a reflection effect in these binaries. The amplitude of the reflection effect can be combined with other data to provide an estimate of the mass of the companion star. We find that the fraction of sdB binaries in our sample which have non-degenerate companions is 0.08±0.06 (1−σ error). These non-degenerate companions have very low masses (≲ 0.1M⊙). This property is not predicted by existing population synthesis models.