Nucleosynthesis in Degenerate Stars
Dr. Evan N. Kirby
Assistant Professor of Astronomy
California Institute of Technology
Explosions of two types of degenerate stars have been incredibly important for astrophysics. First, Type Ia supernovae (the explosions of white dwarfs) have been the centerpiece of the discovery of cosmological acceleration. Nonetheless, we still do not know the mass or the number of the white dwarfs participating in the explosion. I used extragalactic archaeology to infer the nucleosynthesis of Type Ia supernovae that exploded long ago. The abundances of nickel and manganese in long-lived stars show that the white dwarfs detonated below the Chandrasekhar mass. Second, a single neutron star merger is the only observed source of gravitational waves and the only confirmed source of r-process nucleosynthesis. I will present archaeological evidence that neutron star mergers can explain at least some of the r-process in dwarf galaxies but perhaps not in globular clusters.
All interested persons are invited to attend remotely—email physics@nd.edu for information.