Researchers led by the Carnegie Institution for Science in the United States, have identified a binary star called QU Carinae as a possible supernova progenitor.
Type Ia supernovae are violent stellar explosions, observations of their brightness are used to determine distances in the universe and have shown scientists that the cosmos is expanding at an accelerating rate.
The widely accepted theory is that type Ia supernovae are thermonuclear explosions of a white dwarf star that's part of a binary system- two stars that are physically close and orbit around a common centre of mass.
The white dwarf has mass gradually donated to it by its companion. When the white dwarf mass eventually reaches 1.4 times that of the sun, it explodes to produce a type Ia supernova.
Recent studies, some of which involved scientists at Carnegie observatories, have identified sodium gas associated with type Ia supernovae.
This gas might be ejected from the binary's donor star and linger around the system to be detected after the white dwarf explodes. This provides a clue to the progenitor.
Using data from the DuPont telescope of the Las Campanas observatory in Chile, Stella Kafka and her team- Kent Honeycutt of Indiana University and Bob Williams of the Space Telescope Science Institute- looked at these gas signatures and were able to identify a binary star called QU Carinae as a possible supernova progenitor.
It contains a white dwarf, which is accumulating mass from a giant star, and sodium has been detected around the system.
"We are really excited to have identified such a system," Kafka said in a statement.
"Understanding these systems, the nature of the two stars, the manner in which mass is exchanged, and their long-term evolution will give us a comprehensive picture on how binaries can create one of the most important explosions in the universe," Kafka added.
The study will be published in the journal Monthly Notices of the Royal Astronomical Society.
