Miguel Montarges – How do star end their lives ? Challenges, results, and perspectives at high angular resolution

Speaker : Miguel Montarges (Observatoire de Paris)

Title: How do star end their lives ? Challenges, results, and perspectives at high angular resolution
Abstract:  Cool evolved stars, namely asymptotic giant branch stars and red supergiant stars, experience an important mass loss (10^-7 to 10^-4 solar mass per year, while the solar wind represents ~10^-14 solar mass per year). This stellar wind is enriched in heavy elements and contributes to the chemical evolution of the Galaxy. For massive stars, it can determine the final fate of the star as a neutron star or black hole. Yet, some of its mechanisms are still unknown: (1) the dust nucleation process is still unclear, (2) for low and intermediate mass stars the processes shaping planetary nebulae are not well constrained, (3) for massive stars we still do not know how the material is lifted from the photosphere. I will present recent high angular resolution results on cool evolved stars using adaptive optics, and optical and millimeter interferometry. I will conclude the presentation with an overview of a promising future thanks to a powerful new instrumentation.