Place: 4421 Sterling Hall, Coffee and Cookies at 3:30 pm, Talk starts at 3:45 pm
Speaker: Lars Bildsten, KITP, UCSB
Abstract: Some stars unambiguously reveal their 3D nature to the observer (e.g. Betelgeuse),whereas other stars exhibit phenomena which we attribute to physics that is intrinsically multi-dimensional (e.g. convection). It has been a theoretical challenge to realistically model stars in 3D due to the obvious computational hurdles. This is especially true when radiative transfer must also be simultaneously solved through a highly turbulent medium with large density variations. However, computational capabilities have now reached the level where physically realistic 3D RHD models, in our case using Athena++, can be calculated to levels worthy of comparisons to observations in at least two distinct stellar contexts. The first is the outer envelopes of massive stars on the main sequence, where TESS observations are finding surprising temporal variability. The second case we are studying is whole star convective models of luminous red supergiants at the end of their lives. The structure of their outer envelopes is manifest when observed prior to explosion and impacts the early part of the supernovae light-curves, especially the initial shock breakout.