Scientists watched a star explode in real time for the first time ever

 For the first time, astronomers witnessed a massive star explode in a flaming supernova, and the experience was far more intense than they had anticipated.

 

According to a recent study published Jan. 6 in the Astrophysical Journal, scientists started observing the dying star, a red supergiant known as SN 2020tlf that is 120 million light-years from Earth, more than 100 days before its last, cataclysmic collapse. The star erupted with intense flashes of light during that period, and huge globs of gas exploded out of the star's surface.

 

An artist's rendition of a red supergiant star transitioning into a Type II supernova, emitting a violent eruption of radiation and gas on its dying breath before collapsing and exploding. (Image credit: W. M. Keck Observatory/Adam Makarenko)

 

The researchers claimed that earlier observations of red supergiants on the verge of exploding showed no signs of strong emissions, thus these pre-supernova fireworks were a huge surprise.

Wynn Jacobson-Galán, a research scholar at the University of California, Berkeley, who is the primary study author, stated in a statement, "This is a breakthrough in our understanding of what huge stars do moments before they die." "We witnessed a red supergiant starburst for the first time!"

When big stars go boom

 

The volume of red supergiant stars, which may reach hundreds or perhaps more than a thousand times the radius of the sun, makes them the largest stars in the cosmos. Red supergiants are neither the brightest nor the largest stars in the universe, despite their bulk.

Similar to our sun, the nuclear fusion of atoms in the centers of these enormous stars produces energy. Red supergiants, however, can create considerably heavier elements than the hydrogen and helium that our sunburns with because they are so large. Supergiants' cores heat up and pressurize as they burn ever-more-massive materials. These stars eventually run out of energy, their cores collapse, and they violently blast their gaseous outer atmospheres into space in a type II supernova explosion before they can begin fusing iron and nickel.

Scientists have studied the aftermath of these cosmic explosions and have observed red supergiants before they go supernova, but they have never witnessed the entire process in action until now.

In the summer of 2020, the team behind the new study started studying SN 2020tlf as it flickered with brilliant bursts of radiation that they later determined to be gas erupting off the star's surface. The University of Hawaii Institute for Astronomy Pan-STARRS1 telescope and the W. M. Keck Observatory on Mauna Kea were the two Hawaii telescopes the astronomers used to observe the irritable star for 130 days. Finally, the star went boom at the conclusion of that time.

At the moment of the explosion, the scientists observed evidence of a dense cloud of gas encircling the star; this cloud of gas was probably the same as that which the star had previously ejected, according to the researchers. This shows that the star's cataclysmic explosions began occurring long before the core of the star collapsed in the fall of 2020.

Raffaella Margutti, an astrophysicist at UC Berkeley and study co-author, said in a release, "We've never confirmed such dramatic activity in a dying red supergiant star where we observe it emit such a brilliant emission, then collapse and combust, until now.

The scientists came to the conclusion that these findings indicate red supergiants suffer major internal structural changes that result in uncontrolled gas explosions in the months just prior to crashing.