2008/04/15 by Xuefei Chen, Zhanwen Han · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13334.x
16 pages, 17 figures. accepted by MNRAS
arxiv created 2008/04/15 · openalex publication_date 2008/06/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Binary population synthesis shows that mass transfer from a giant star to a main-sequence (MS) companion may account for some observed long-orbital-period blue stragglers. However, little attention is paid to this blue straggler formation scenario as dynamical instability often happens when the mass donor is a giant star. In this paper, we have studied the critical mass ratio, qc, for dynamically stable mass transfer from a giant star to a MS companion using detailed evolution calculations. The results show that a more evolved star is generally less stable for Roche lobe overflow. Meanwhile, qc almost linearly increases with the amount of the mass and angular momentum lost during mass transfer, but has little dependance on stellar wind. To conveniently use the result, we give a fit of qc as a function of the stellar radius at the onset of Roche lobe overflow and of the mass-transfer efficiency during the Roche lobe overflow. To examine the formation of blue stragglers from mass transfer between giants and MS stars, we have performed Monte Carlo simulations with various qc. The simulations show that some binaries with the mass donor on the first giant branch may contribute to blue stragglers with qc obtained in this paper but will not from previous qc. Meanwhile, from our qc, blue stragglers from the mass transfer between an asymptotic giant branch star and a MS companion may be more numerous and have a wider range of orbital periods than those from the other qc.