Mariko Kato1 and Izumi Hachisu2
Abstract.
Recurrent novae are binaries harboring a very massive white dwarf (WD),
as massive as the Chandrasekhar mass, because of their short recurrence
periods of nova outbursts of 10-100 years. Thus, recurrent novae
are considered as candidates of progenitors of Type Ia supernovae (SNe~Ia).
In fact, the SN Ia PTF 11kx showed evidence that its progenitor is
a symbiotic recurrent nova.
The binary parameters of recurrent novae have been well determined,
especially for the ones with frequent outbursts, U Sco and RS Oph,
which provide useful information on the elementary processes
in binary evolution toward SNe~Ia.
Therefore we use them as testbeds for binary evolution models.
For example, the original double degenerate (DD) scenario cannot
reproduce RS Oph type recurrent novae,
whereas the new single degenerate (SD) scenario
proposed by Hachisu et al. (1999) naturally can.
We review main differences between the SD and DD scenarios,
especially for their basic processes of binary evolution.
We also discuss observational support for each physical process.
The original DD scenario is based on the physics in 1980s,
whereas the SD scenario on more recent physics including the new opacity,
mass-growth efficiency of WDs, and optically thick winds developed
in nova outbursts.
Keywords: binaries: general - novae, cataclysmic variables - stars: mass-loss -
white dwarfs - supernovae: general
1Keio University, Hiyoshi, Kouhoku-ku, Yokohama, 223-8521, Japan
2Dept. of Earth Science and Astronomy, College of Arts and Sciences, The University of Tokyo, Komaba,
Meguro-ku, Tokyo 153-8902, Japan