Web edition: September 28, 2012
The bubble-shaped remnant of SN 1006, a type 1a supernova, reveals that two white dwarf stars probably triggered the massive stellar explosion, which went off more than a millennium ago.
Type 1a supernovas ignite when a white dwarf steals too much mass from an orbiting companion star — though the population of objects that serves as victim to such stellar burgling is uncertain.
A team of astronomers searching SN 1006’s 60-light-year-wide remnant for a large companion (which would now be zooming away from the explosion’s epicenter) came up empty. The result, published in the Sept. 27 Nature, suggests either that the explosion involved two white dwarf stars, both of which were obliterated by the blast, or that the doomed dwarf’s companion was smaller than the sun.
J. Gonzalez Hernandez et al. No surviving evolved companions of the progenitor of SN 1006. Nature. Vol. 489, September 27, 2012, p. 533.