Dr. JJ Hermes – Real-Life Death Stars: Measuring the Composition of Rocks on Alien Planets by Tearing Them Apart

White dwarf stars are the endpoints of all low-mass stars, including our Sun, and their high density means that all heavy elements rapidly settle out of their atmospheres. However, a large fraction of white dwarfs show heavy metals like calcium, oxygen, magnesium, and iron in their atmospheres. Dr. Hermes will discuss observations of the violent ends to many close-in planets and asteroids that are ripped apart and pollute white dwarf stars, revealing the bulk composition of rocky alien worlds.

Dr. JJ Hermes is an assistant professor in the Department of Astronomy at Boston University, focused on high-precision observations of the endpoints of stars, planets, and binary systems. Before moving to Boston in 2019, Dr. Hermes was a Hubble Fellow at the University of North Carolina Chapel Hill, an ERC postdoctoral fellow at the University of Warwick in central England, and he completed a Ph.D. at the University of Texas at Austin.