Observational studies of evolved stars, mainly AGB stars and red supergiants, using ALMA

We are happy to announce a Lund Observatory seminar to be given by Hans Olofson from Chalmers. Hans is an expert on observations of evolved stars and will tell us about his new work enabled by ALMA. A title and abstract are provided below.

Observational studies of evolved stars, mainly AGB stars and red supergiants, using ALMA

Abstract:  The high sensitivity and high angular resolution of the Atacama Large Millimeter/submillimeter Array (ALMA) have made it possible to study many aspects of evolved stars in unprecedented detail. A number of AGB stars are close enough and large enough to allow detailed studies of the physical properties of their surfaces and extended atmospheres. Likewise, it is possible to study the initial chemical processes that lead to the formation of dust grains and molecules, and then follow how these species are altered as the material leaves the star in an intense wind that eventually interacts with the interstellar medium. The wind, or mass-loss, determines the final evolution of AGB stars, and its characteristics are important inputs to population synthesis and galactic chemical evolution models. Yet, the observational constraints on many of its properties are meagre, but ALMA is adding new insights. Finally, the spectacular transformation from essentially spherical AGB stars to the geometrically complex planetary nebulae, most likely a consequence of binary evolution, is possible to follow in more detail than ever before. I will highlight some of the work in this context done by the evolved stars group at Chalmers using ALMA.

Time and place: 6 February, 13.15, Lundmark lecture hall, Sölvegatan 27