Episode 311 - Stellar deaths, black holes, white dwarf accomplices and crystal stars

What happens when a star dies? We can investigate what is left behind at the scene of the crime to piece together the final moments of a star. Some become white dwarfs so cold and cool they crystallize with thick oxygen and carbon skins. Others collapse in on themselves becoming supernova in a catastrophic core collapse. But sometimes in complex binary systems there is an accomplice that pushes the star over the edge, into supernova territory. Plus super massive black holes can devour passing stars, but sometimes they have a little help. Pier-Emmanuel Tremblay, Gilles Fontaine, Nicola Pietro Gentile Fusillo, Bart H. Dunlap, Boris T. Gänsicke, Mark A. Hollands, J. J. Hermes, Thomas R. Marsh, Elena Cukanovaite, Tim Cunningham. Core crystallization and pile-up in the cooling sequence of evolving white dwarfs. Nature, 2019; 565 (7738): 202 DOI: 10.1038/s41586-018-0791-x Graham ML et al. Delayed Circumstellar Interaction for Type Ia SN 2015cp Revealed by an HST Ultraviolet Imaging Survey. The Astrophysical Journal, 2019 Dheeraj R. Pasham, Ronald A. Remillard, P. Chris Fragile, Alessia Franchini, Nicholas C. Stone, Giuseppe Lodato, Jeroen Homan, Deepto Chakrabarty, Frederick K. Baganoff, James F. Steiner, Eric R. Coughlin, Nishanth R. Pasham. A loud quasi-periodic oscillation after a star is disrupted by a massive black hole. Science, Jan. 9, 2019; DOI: 10.1126/science.aar7480