RVs of binaries black hole/Sun-like stars

However, the number of those binary systems that survive the binary evolution and black hole formation is uncertain by multiple orders of magnitude. The survival rate is particularly uncertain for massive stars with low-mass companions, which are thought to be the progenitors of most black hole X-ray binaries.

We present a search for close black hole companions (orbital period <~3 days, equivalent to separation <~20R_{sun}_) to AFGK-type stars in TESS, i.e. the non-accreting counterparts to and progenitors of low-mass X-ray binaries. Such black holes can be detected by the tidally induced ellipsoidal deformation of the visible star, and the ensuing photometric light-curve variations. From an initial sample of 4.7x10^6^ TESS stars, we have selected 457 candidates for such variations.