Categories: supernova

A Black Hole or Neutron Star Fell Into Another Star and Triggered a Supernova

What happens when you slam a neutron star (or black hole, take your pick) into a companion star? A supernova, that’s what. And for the first time ever, astronomers think they’ve spotted one.

Back in 2014 the MAXI instrument aboard the International Space Station detected a flare of X-rays from a dwarf, star-forming galaxy sitting 480 million light-years away from us. No big deal; it happens all the time.

Around the same time, a radio survey using the National Science Foundation’s Karl G. Jansky Very Large Array (VLA) called the Faint Images of the Radio Sky at Twenty centimeters (FIRST) didn’t find anything unusual in that patch of the sky. Also no big deal.

But then a follow-up survey, the Very Large Array Sky Survey (VLASS) which began observations in 2017, did find something: a bright source of radio emissions coming from the same place. Big deal.

The astronomers behind the survey think they’ve spotted something remarkable. A supernova detonation triggered by a massive case of stellar indigestion; a star consuming a companion black hole or neutron star.

“Theorists had predicted that this could happen, but this is the first time we’ve actually seen such an event,” said Dillon Dong, a graduate student at Caltech and lead author on a paper reporting the discovery in the journal Science.

Here’s what went down in that galaxy far, far away. One star in the binary pair ended its life, destroying itself as a supernova and leaving behind a remnant, either a neutron star or a black hole. Then over the ages that dense remnant swirled closer and closer to its surviving sibling. About 300 years ago, it entered the atmosphere of that companion star. Tearing apart the star, it sent material flinging away into space. Once it reached the core, it disrupted the fusion reactions happening there. Without a source of energy to sustain itself, the star went supernova, giving off the flash of X-rays.

“That jet is what produced the X-rays seen by the MAXI instrument aboard the International Space Station, and this confirms the date of this event in 2014,” Dong said.

Now, the material ejected from 2014 event raced outwards, eventually colliding with the older material thrown out when the dense companion first entered the star, creating shock waves that produced the radio emissions.

“All the pieces of this puzzle fit together to tell this amazing story,” said Gregg Hallinan of Caltech. “The remnant of a star that exploded a long time ago plunged into its companion, causing it, too, to explode,” he added.

Paul M. Sutter

Astrophysicist, Author, Host |

Recent Posts

Astronomers see Tantalizing Evidence for one of the First Stars to Form in the Universe

In a recent study, a team led by the University of Tokyo believe they have…

4 hours ago

While SLS is Delayed, Crew-5 Zips in and Launches to the International Space Station

A new crew is on the way to the International Space Station, and the crew…

5 hours ago

Here are the High-Resolution Images of Europa Captured by Juno During its Recent Flyby

It's been over twenty-two years since we’ve been able to see Jupiter’s enticing moon Europa…

6 hours ago

How Should the World’s Governments Respond if We Detect an Alien Civilization?

Science fiction is the realm where people traditionally wrestle with the idea of contact with…

1 day ago

A Year After a Failed Launch, Firefly Reaches Orbit and Deploys Satellites

Edited on 10/6/22 to add new information from Seradata. Commercial space company Firefly Aerospace successfully…

1 day ago

27 to 78 cm of sea Level Rise Could be Locked in From Melting Greenland ice Caps

Recent climate research, published in the Nature Climate Change journal has confirmed that melting icecaps…

2 days ago