Super Asymptotic Giant Branch (Super-AGB) stars reside in the mass
range ~ 6.5-10 Msun and are characterised by off-centre carbon
ignition prior to a thermally pulsing phase which can consist of many
tens to even thousands of thermal pulses. The final fate of these
stars is quite uncertain and depends primarily on the competition
between the core growth and mass-loss rates. If the stellar envelope
is removed prior to the core reaching the Chandrasekhar mass, an O-Ne
white dwarf will remain, otherwise the star will undergo an
electron-capture supernova leaving behind a neutron star. I describe
the factors which influence these different final fate channels,
determine their relative fractions and provide a mass limit for the
lowest mass supernova over a broad range of metallicities.
|