An artist’s impression of a supernova – SN2016iet – going off in a dense stellar environment. Image: Gemini Observatory/NSF/AURA/ illustration by Joy Pollard
Astronomers have found an apparent pair-instability supernova, the explosion of a star 200 times more massive than the Sun in a previously uncharted dwarf galaxy some one billion light years away. It is the most massive star yet found to undergo a supernova blast and may reflect how huge, metal-poor stars that formed in the immediate aftermath of the big bang ended their lives.
But the devil is in the details, and the observations do not exactly match theoretical expectations.
“Everything about this supernova looks different, its change in brightness with time, its spectrum, the galaxy it is located in and even where it’s located within its galaxy,” said Edo Berger, an astronomer at Harvard University and a co-author of a paper in the Astrophysical Journal. “We sometimes see supernovas that are unusual in one respect, but otherwise are normal. This one is unique in every possible way.”
The supernova, catalogued as SN2016iet, was first noticed in 2016 by the European Space Agency’s Gaia satellite. Followup-up studies utilised a variety of instruments, including the CfA/Harvard & Smithsonian’s ...