Status : The Asymptotic Giant Branch is a late stage of evolution for stars of initial mass about 0.5 to 8 Mo, following the Horizontal Branch. They have a core of carbon and oxygen, burning helium in a shell, and episodically burning hydrogen in an outer shell. AGB stars loose mass at high rates (1D-7 to 1D-4). They are enshrouded by an expanding circumstellar enveloppe containing molecular gas and dust.

Spectral type : Late K to M10 for oxygen-rich photospheres; C[NR] for carbon-rich photospheres; MS, S, SC for photospheres with C/O ~ 1. Their luminosity types range from III to Ib.

Variability : Miras are AGB stars, as well as most semi-regular variables and some slow irregular variables.

-- CecileLoup - 2014-04-10