2007/03/08 by Izumi Hachisu, Mariko Kato, G. J. M. Luna +1 · 4 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research #astro-ph
paper · pdf · doi:10.1086/516838
to appear in the ApJL, 4 pages including 4 figures
arxiv created 2007/03/08 · openalex publication_date 2007/03/21 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
One of the candidates for Type Ia supernova progenitors, the recurrent nova RS Ophiuchi, underwent its sixth recorded outburst in 2006 February, and for the first time a complete light curve of supersoft X-rays has been obtained. It shows the much earlier emergence and longer duration of a supersoft X-ray phase than expected before. These characteristics can be naturally understood when a significant amount of helium layer piles up beneath the hydrogen-burning zone during the outburst, suggesting that the white dwarf (WD) is effectively growing in mass. We have estimated the WD mass in RS Oph to be 1.35 ± 0.01 M ☉ and the growth rate of the WD mass to be at an average rate of ~1 × 10 -7 M ☉ yr -1 . The white dwarf will probably reach the critical mass for Type Ia explosion if the present accretion continues further for a few to several times 10 5 yr.