2005/11/30 by Marek J. Sarna, M. J. Sarna, Ene Ergma +5
Arts and Humanities · Physics and Astronomy · #Astrophysics (astro-ph) #FOS: Physical sciences #Historical Studies in Science #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0511825
17 pages, 4 figures, submitted to Acta Astronomica
arxiv created 2005/11/30 · openalex publication_date 2005/11/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We perform evolutionary calculations of binary stars to find progenitors of systems with parameters similar to the recurrent nova U Sco. We show that a U Sco-type system may be formed starting with an initial binary system which has a low-mass carbon-oxygen white dwarf as an accretor. Since the evolutionary stage of the secondary is not well known, we calculate sequences with hydrogen-rich and helium-rich secondaries. The evolution of the binary may be divided into several observable stages as: classical nova, supersoft X-ray source with stable hydrogen shell burning, or strong wind phase. It culminates in the formation of a massive white dwarf near the Chandrasekhar mass limit. We follow the chemical evolution of the secondary as well as of the matter lost from the system, and we show that observed 12C/13C and N/C ratios may give some information about the nature of the binary.