Hydrogen Deficiency in Algol Secondaries

Abstract

A study was carried out for 309 Algol systems to show that most of the secondary components of low mass-ratio systems are hydrogen deficient stars. This hydrogen deficiency is evident from their positions on a Δ log L — Δ log T plot, where Δ is the difference between the observed quantity, log L or log Te, and the value of the same quantity for a star of the same mass on the empirical Main Sequence. The secondary components are shown to occupy the region of mass losing helium dwarfs on this plot. A correlation has also been obtained between the excess of effective temperature and the mass ratio of the system.