  We have been proposing two evolutionary paths to Type Ia supernovae (SNe Ia),
which are called the supersoft X-ray source (SSS) channel and the symbiotic
channel, depending on the orbital separation just prior to an SN Ia explosion.
The essential difference of our treatment is inclusion of strong, optically
thick winds on mass-accreting white dwarfs (WDs) in binary evolutions when the
mass accretion rate on to WDs exceeds a critical rate of ~ 1 x 10^{-6} Mo/yr.
Once optically thick winds blow from the WD, the binary can avoid forming a
common envelope in some cases. So that the WDs are able to grow up to the
Chandrasekhar mass and explode as an SN Ia, showing SSS or recurrent nova
phenomena in the way to SNe Ia. Thus, the accretion wind process of WDs can
open new channels to SNe Ia. We have modeled the LMC supersoft source RX
J0513.9-6951 as an example of the systems in the accretion wind phase. Further
inclusions of two other elementary processes make the channels much wider;
these are the case BB mass transfer in the SSS channel and the strong orbital
shrinkage during the superwind phase of the primary star in the symbiotic
channel. As a result, the estimated birth rate of SNe Ia via these two channels
becomes compatible with the observation in our Galaxy. Interestingly, the U Sco
and T CrB subclasses of recurrent novae can be naturally understood as a part
of evolutionary stages in these two SSS and symbiotic channels to SNe Ia,
respectively. Thus we have a unified picture of binary evolutions to SNe Ia,
luminous SSS, and recurrent novae.

Astrophysics