The explosions of stars are some of the most stunning and amazing phenomena found in the universe. Yet a recently observed supernova conflicts with the models for the demise of gigantic stars.
In November 2016, the European Space Agency’s Gaia satellite spotted something intriguing. Astronomers utilized follow-up observations over the past three years trying to comprehend what they saw.
Supernova SN2016iet challenged their desires, and now, cosmologists believe that it’s the remnants of the most massive star to be obliterated by a supernova, as per a study published Thursday in The Astrophysical Journal.
The supernova has a lot of energy, long duration, unexpected chemical signatures, and a metal-poor environment. That doesn’t coordinate with anything astronomers have seen previously.
“When we first realized how thoroughly unusual SN2016iet is my reaction was ‘whoa — did something go horribly wrong with our data?’ ” said lead study author Sebastian Gomez, a Harvard University graduate student. “After a while, we determined that SN2016iet is an incredible mystery, located in a previously uncatalogued galaxy one billion light-years from Earth.”
Multiple telescopes were utilized to observe the supernova, including the Magellan Telescopes at Las Campanas Observatory in Chile and the Center for Astrophysics Harvard and Smithsonian’s MMT Observatory in Arizona.
“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 study co-author Edo Berger, a Harvard University astronomy professor. “We sometimes see supernovas that are unusual in one respect, but otherwise are normal; this one is unique in every possible way.”
Prior to the blast, the star was 200 times the mass of the sun. Astronomers believe it formed by itself 54,000 light-years from the center of a dwarf galaxy, which is additionally puzzling.
As far as a star’s life, this one was short. It lasted only a few million years, losing 85% of its mass over that time. At that point, when the star detonated, the debris and jetsam collided with the material the star had shed over time, making the peculiar appearance of the supernova that is visible to astronomers today.
“The idea of pair-instability supernovas has been around for decades,” Berger said. “But finally having the first observational example that puts a dying star in the right regime of mass, with the right behavior, and in a metal-poor dwarf galaxy is an incredible step forward. SN2016iet represents the way in which the most massive stars in the universe, including the first stars, die.”
Astronomers presently can’t seem to find the first stars since none of them most likely exist any longer, exploding in supernovae to populate the universe with heavy elements. Studying this supernova can inform astronomers about what those stars like and how they died.
The astronomers will keep observing this supernova to learn more about how it formed and how it could change later on.
“Most supernovas fade away and become invisible against the glare of their host galaxies within a few months. But because SN2016iet is so bright and so isolated we can study its evolution for years to come,” Gomez said. “These observations are already in progress and we can’t wait to see what other surprises this supernova has in store for us.”