LBVs, hypergiants and impostors — the evidence for high mass loss events

Abstract

Mass loss from massive stars is common. It plays an important role in the evolution of stars above about 20 Mʘ. In the massive hot stars the winds and mass loss are driven by radiation pressure on the lines. The mass loss mechanism in post-main sequence red supergiants is still debated but pulsation and convection play a role. In this short talk, I am emphasizing the evidence for high mass loss episodes in evolved massive stars with specific examples such as VY CMa, IRC +10420 and the giant eruptions of LBVs, the possible origin of these episodes, and their importance in the final stages of massive star evolution. By analogy with the less massive AGB stars, I suggest that VY CMa is a candidate for a second red supergiant stage.