Red supergiants and stellar evolution

EKSTROM, S.; GEORGY, C.; MEYNET, G.; GROH, J.; GRANADA, A.

Paris

Workshop; Betelgeuse workshop; 2012

We review the significant role played by red supergiants (RSGs) in stellarpopulations, and some challenges and questions they raise for theoreticalstellar evolution. We present how metallicity and rotation modify the way starsgo to the red part of the Hertzsprung- Russell diagram or come back from it,and how RSGs might keep a trace of their main-sequence evolution. We comparetheoretical popu- lation ratios with observed ones.