Scialog: Collaborative Teams - 2017
Astronomy, University of California, Santa Cruz
Down but not out: the white dwarf survivors of low-luminosity thermonuclear supernovae,
Scientists often can learn a lot by studying exceptions to the rule, and that certainly holds true with astrophysicists who study stars. Ryan Foley, University of California, Santa Cruz, and James Fuller, California Institute of Technology, recently formed a team and won a funding competition that will allow them to study an oddball class of white dwarf stars.
White dwarfs generally are the result of Type 1a supernovae – titanic explosions that occur in binary systems (two stars orbiting one another). In the events leading up to a Type 1a explosion, a white dwarf star, called the “progenitor,” initially draws material off its binary companion, which could be anything from a red giant to another, smaller, white dwarf. So, in a Type 1a event there is a white dwarf involved before the explosion, which results in a white dwarf (not necessarily the same one) after the explosion. However, in rare instances, at the low end of the energy scale when it comes to Type 1a supernovae a progenitor white dwarf may survive the explosion, a so-called “post-genitor.” It is estimated there are roughly one million such post-genitor stars in the Milky Way.
Foley and Fuller note, “These survivors are battered and bruised stars that should have distinct observational properties.” And that offers unique opportunities to advance our knowledge of how stars behave. Foley and Fuller propose to establish the relationship between peculiar thermonuclear transients and white dwarf progenitor systems by directly detecting and characterizing bound white dwarf post-genitors at the centers of supernova remnants.
The two scientists formed their collaboration at an RCSA-sponsored conference, Scialog: Time Domain Astrophysics, held late last year in Tucson, Arizona. There, 50 leading young astronomers and astrophysicists, joined by 10 distinguished senior scientists, engaged in intensive discussions designed to produce creative ideas for innovative research. (Scialog is a combination of “science” and “dialog.”)
“Scialog aims to encourage collaborations among theorists, experimentalists and computational scientists,” said RCSA Program Director Richard Wiener. “We want to catalyze the development of a community in which theory and observation work together to achieve understanding of fundamental phenomena.”