Stellar Evolution through the Lens of SOFIA - Highlights of Evolved Star Investigations

Over the last decade, the astronomical community used the Stratospheric Observatory for Infrared Astronomy (SOFIA) to investigate nearly every phase of stellar evolution. Evolved stars, which have left the main sequence, were particularly well suited for study with the suite of instruments on SOFIA. Targets of such studies included asymptotic giant branch (AGB) stars, red supergiants, Wolf-Rayet stars, luminous blue variables, novae, post-AGB stars, planetary nebulae, and supernova remnants. These objects are actively shedding or have recently shed the bulk of their mass, and this newly enriched material will be recycled into the next generations of stars and planets. The grains and molecules that are forming in and around these evolved sources have a plethora of signatures in the infrared with which to trace the physical and chemical conditions of the gas and dust and that of the stars which produced them. This talk reviews some of the discoveries and new insights that came from observations with EXES, FIFI-LS, FLITECAM, FORCAST, GREAT, and HAWC+, advancing our understanding of evolved stars and stellar evolution. Many thanks to the SOFIA instrument teams, flight crews, and staff scientists for making these studies possible, including building the instruments, making the observations, and creating high-quality data products, and to the science teams whose work is reviewed here. SOFIA was jointly operated by the Universities Space Research Association, Inc. (USRA), under NASA contract NNA17BF53C, and the Deutsches SOFIA Institut (DSI) under DLR contract 50 OK 0901 to the University of Stuttgart.