For The First Time, We've Seen a Red Giant Star Transition Into a Supernova

We're observing many remarkable sights out in space as our telescopes become more powerful, but there's a new candidate for the most exciting one yet: According to astronomers, we've detected a red supergiant star exploding into a supernova for the first time.

 

Supernova (SN) 2020tlf, to give it its technical name, was observed for 130 days leading up to the gigantic blast, the result of the decease of a star some 120 million light-years away from Earth in the NGC 5731 galaxy and about 10 times bigger than our own Sun.

 

Astronomers says that this extraordinary look at one of the most mesmerizing and large-scale events in the Universe shows that there isn't always a 'calm before the storm' in terms of supernova booms – something that challenges earlier assumptions.

'This is a breakthrough in our understanding of what massive stars do instants before they die,' says Wynn Jacobson-Galán, an astrophysicist from the University of California, Berkeley, and the study's lead author.

Supernovas happen when massive stars die, or run out of fuel and collapse in on themselves, no longer to keep the forces of gravity and nuclear reactions in balance. A giant, super-bright explosion follows the collapse, sending shock waves through space, and usually leaving a dense core surrounded by a cloud of gas called a nebula.

'Direct discovery of pre-supernova activity in a red supergiant star has never been detected before in an ordinary Type II supernova. For the first time, we observed a red supergiant star explode!' 

This dramatic process has never been seen in real time before, though. Two telescopes were involved in making the observations, both on Hawaii: the University of Hawaii Institute for Astronomy Pan-STARRS on Haleakalā, Maui, and the WM Keck Observatory on Mauna Kea, Hawaii Island.

 

The collected data is already providing new insights. There was direct evidence of dense circumstellar material surrounding the star when it exploded, for example, which the researchers think was the same gas they had spotted being ejected from the red supergiant several months before.

 

References: ScienceAlert, Astrophysical Journal