https://doi.org/10.1140/epjd/s10053-021-00166-9
Regular Article - Plasma Physics
The evolution of primary stars (30–40 
) in massive close binary systems
Astronomical Observatory, Volgina 7, Belgrade, Serbia
Received:
14
December
2020
Accepted:
29
April
2021
Published online:
28
May
2021
We present evolutionary models of primary stars with initial masses in the range of 30 to 40 , evolving in massive binary systems, possible progenitors of gravitational wave sources. The binary systems have an initial mass ratio of 0.9, an initial orbital period of 3 days and an accretion efficiency of 10%. The evolution of the primary stars in those systems is followed from the main sequence to the formation of the carbon-oxygen core. In addition, the evolution of two primaries with the lowest initial masses is calculated to the iron core formation. The masses of the helium and carbon-oxygen cores formed in primary stars are compared with the masses of cores formed in single stars with the same initial masses. The initial mass limit for the black hole formation for this selected type of massive binaries is established between 32 and 34 . All models are calculated with the MESA (Modules for Experiments in Stellar Astrophysics) numerical code.
© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2021
