In a world-first, astronomers have recorded the earliest moments of a supernova — the powerful explosion of a massive star — in unprecedented detail. The observation is a celebratory moment in the world of astronomy that could help improve our knowledge about what happens to stars the moment they die.
The astrophysicists behind the study used data captured by NASA’s Kepler space telescope in 2017, recording the initial light burst from a supernova as a shockwave blasted its way through a star. According to the researchers, the star that exploded was likely a yellow supergiant, which is more than 100 times bigger than our sun.
The initial brightening phase of a supernova has never been fully observed before, said Patrick Armstrong, a Ph.D. student at the Australian National University and the study’s first author. “In order to capture this, you have to be looking at the right part of the sky, at the right time, with the right amount of detail, to be able to see everything,” said Armstrong.
The supernova, named SN2017jgh, was more than one billion light-years away, meaning that the light observed by the telescope was actually one billion years old. A supernova explodes rapidly but it can take months to brighten and then eventually dim, while the early explosion is observable for only a few days.
As reported by The Guardian, the researchers made the discovery based on a “shock cooling light curve,” which measured the change in the amount of light emitted by the supernova over time.
“We see in the night sky this tiny point of light get brighter and brighter … as the supernova explodes, and [then] get dimmer,” said Armstrong. “This is the first time we’ve ever seen the shock cooling light curve in complete detail.”
According to Armstrong, the observation helped scientists to better understand what stars explode into different supernovae. “Normally we can’t get much information about these stars because they have exploded and there’s not much left to look at.”
Study source: Monthly Notices of the Royal Astronomical Society — SN2017jgh – A high-cadence complete shock cooling lightcurve of a SN IIb with the Kepler telescope
