Categories: AstronomyBlack Holes

A ring of high-energy particles surrounding a black hole suddenly disappeared

In March 2018 astronomers watched a massive black hole surge in brightness. Then over the following year, its ring of light dimmed to near-invisibility before regaining its former strength. The potential culprit? The black hole swallowing an entire star.

The neighborhood of a black hole is, to put it mildly, a nasty place. And it’s especially bad near the biggest black holes in the universe, known as supermassive black holes. As gas and dust falls towards the event horizon, it crowds together in a tight, bright ring of swirling energies, ripping itself apart in a tremendous inferno. This disk spins and spins, generating massive magnetic and electric fields that twist the distort the flows of gas.

Sometimes those magnetic fields – especially the ones near the monster itself – become so entangled that they snap like over-stretched rubber bands, releasing a flood of deadly X-ray radiation. Astronomers observe this radiation in the form of a “corona”, haloing the black hole in the center.

Artist’s impression of a black hole’s corona disappearing and reappearing. Image credit: NASA/JPL-Caltech

So all this is suitably awesome, but something went awry with one particular monster black hole known as 1ES 1927+654. In March 2018, astronomers with the All-Sky Automated Survey for Super-Novae (ASSASN) watched as this otherwise-normal system surged in brightness by over 40 times.

But after that flare-up, follow-up observations with NASA’s NICER, an X-ray telescope on the International Space Station, showed a steep decline in brightness. Over the course of a single year, the X-ray corona dimmed by a factor of over 10,000.

Slowly, ever so slowly, the black hole’s corona returned to its former glory.

The only explanation that makes sense, as reported in a recent paper published in The Astrophysical Journal, is that the black hole ate an entire star.

As the star approached the embrace of the black hole’s event horizon, the extreme gravity ripped it to shreds, releasing the burst of energy that ASSASN spotted. But as it spiraled inwards, the star was like a nuclear bull in a china shop, smashing through the complex webs of magnetic fields lines. Without the magnetic fields to shape and funnel the surrounding gas, all activity near the black hole ceased.

It wasn’t until years later (well after it finished its stellar meal) that the black hole could reassert control over the situation and replace its corona.

At least, that’s what we think. When it comes to some of the most energetic and complex events in the universe, sometimes a good guess is all we’ve got.

Paul M. Sutter

Astrophysicist, Author, Host |

Recent Posts

Jupiter’s “Stripes” Change Color. Now We Might Know Why

While Jupiter’s Great Red Spot is one of the most well-known spectacles in the solar…

21 hours ago

Astronomers are Searching for a Galaxy-Wide Transmitter Beacon at the Center of the Milky Way

Researchers with the SETI Institute have monitored the center of the Milky Way for possible…

2 days ago

Betelgeuse is Almost 50% Brighter Than Normal. What’s Going On?

Whenever something happens with Betelgeuse, speculations about it exploding as a supernova proliferate. It would…

2 days ago

Three New Astronauts Arrive at the Chinese Space Station, Including the Country's First Civilian

China's Shenzou-16 mission just delivered three taikonauts to the Tiangong space station, performing the most…

2 days ago

These New Computer Simulations of the Sun are Hypnotic

It's almost impossible to over-emphasize the primal, raging, natural power of a star. Our Sun…

3 days ago

JWST Scans an Ultra-Hot Jupiter’s Atmosphere

When astronomers discovered WASP-18b in 2009, they uncovered one of the most unusual planets ever…

3 days ago