Observations of Exploding Star in ‘Real Time’ Deemed a Major Step Towards Predicting Supernovas

Observations of Exploding Star in ‘Real Time’ Deemed a Major Step Towards Predicting Supernovas
Big-badda-boom: Supernova SN 2020fqv. (Image: NASA, ESA, Ryan Foley (UC Santa Cruz), Joseph DePasquale (STScI))

A star located 60 million light years away went supernova last year, and astronomers managed to capture all stages of the stellar explosion using telescopes both on the ground and in space.

The doomed star has been known to astronomers for quite some time, but in April 2020, it suddenly went supernova, earning it the designation SN 2020fqv. The Zwicky Transient Facility at the Palomar Observatory in San Diego, California, happened to be watching, as was NASA’s Transiting Exoplanet Survey Satellite (TESS), which is normally used to detect distant exoplanets. Alerted to the rare event, astronomers then scrambled to get the Hubble Space Telescope involved, among several other ground-based telescopes.

This awesome display of astronomical power has yielded a dataset of unprecedented proportions, with independent observations gathered before, during, and after the explosion. It’s providing a rare multifaceted view of a supernova during its earliest phase of destruction. The resulting data should vastly improve our understanding of the processes involved when stars go supernova, and possibly lead to an early warning system in which astronomers can predict the timing of such events.

The location of SN 2020fqv within its host galaxy.  (Image: NASA, ESA, Ryan Foley (UC Santa Cruz), Joseph DePasquale (STScI)) The location of SN 2020fqv within its host galaxy. (Image: NASA, ESA, Ryan Foley (UC Santa Cruz), Joseph DePasquale (STScI))

“We used to talk about supernova work like we were crime scene investigators, where we would show up after the fact and try to figure out what happened to that star,” Ryan Foley, an astronomer at the University of California, Santa Cruz, and the leader of the investigation, explained in a press release. “This is a different situation, because we really know what’s going on and we actually see the death in real time.”

Of course, it took 60 million years for the light from this supernova to reach Earth, so it’s not exactly happening in “real time,” but you get what Foley is saying. SN 2020fqv is located in the Butterfly Galaxies — a pair of interacting galaxies — and it can be spotted in the Virgo constellation.

Observations of circumstellar material in close proximity to the star were made by Hubble just hours after the explosion, which, wow. The star shed this material during the past year, offering a unique perspective of the various stages that occur just prior to a supernova explosion.

“We rarely get to examine this very close-in circumstellar material since it is only visible for a very short time, and we usually don’t start observing a supernova until at least a few days after the explosion,” said Samaporn Tinyanont, the lead author of the paper, which is set for publication in the Monthly Notices of the Royal Astronomical Society.

That stars become more active prior to an explosion is known, Betelgeuse being a good example. This red giant star has been belching out a lot of material lately, and while it may not go supernova any time soon, it’s clearly exhibiting the tell-tale signs of its imminent destruction.

TESS managed to capture one image of the evolving system every 30 minutes, starting a few days before the explosion and ending several weeks afterward. Hubble joined in on the action a few hours after the explosion was first detected. Archival data dating back to the 1990s was also brought in for the analysis, resulting in an unprecedented multi-decade survey of a star on its way out.

Among the new results is an accurate weighing of the doomed star, which the team did by using multiple astronomical methods. At the time of the explosion, the star was 14 to 15 times the mass of our Sun — a critical piece of insight that will help astronomers to understand the physical conditions in place as a star enters into its death throes.

In the press release, the researchers referred to SN 2020fqv as the “Rosetta Stone of supernovas,” as the new observations could translate hidden or poorly understood signals into meaningful data.

“This could be a warning system,” said Foley. “So if you see a star start to shake around a bit, start acting up, then maybe we should pay more attention and really try to understand what’s going on there before it explodes.” To which he added: “As we find more and more of these supernovas with this sort of excellent data set, we’ll be able to understand better what’s happening in the last few years of a star’s life.”

More: A vanished supernova will reappear in 16 years.