Black holes — the supermassive gravitation forces at the center of most galaxies — actually spend much of their time dormant, or essentially asleep. Astronomers have now spotted one not only waking up but appearing to hit the celestial equivalent of a snooze button every few days.
The black hole at the center of a galaxy named SDSS1335+0728, about 300 million light-years away, first showed signs of stirring when, in 2019, the galaxy started shining brightly. But since 2024, that black hole the astronomers nicknamed “Ansky” started producing X-ray bursts at regular intervals — almost as if Ansky was stretching, then going back to sleep for a bit, according to a paper in the journal Nature Astronomy.
Rare Black Hole Awakening
Observing a black hole rising into action is relatively rare. Capturing the regular bursts of energy called quasiperiodic eruptions (QPEs) is rarer still.
“And this is the first time we have observed such an event in a black hole that seems to be waking up,” Lorena Hernández-García, an astronomer at Valparaiso University, Chile, and an author of the paper, said in a press release.
They certainly have a good view. Multiple X-ray space telescopes are checking in on Ansky, including XMM-Newton and NASA’s NICER, Chandra, and NASA’s Swift. After the first observed emission, they consulted archive data from another instrument but didn’t find any evidence of earlier emissions.
Read More: JWST Findings May Suggest Our Universe Exists Inside a Black Hole
Understanding Black Hole Mechanics
These observations could alter understandings of how black holes work — or, at least, what causes QPEs. Conventional wisdom is that a black hole’s powerful gravity sucks in any object that dares venture too close, then rips that matter apart. That captured matter then spreads into a hot, bright, rapidly spinning flat circular object called an accretion disc.
QPEs are thought to occur when another object — say a star or a smaller black hole — interacts with that disc. But so far, there is no evidence that Ansky has destroyed a star.
The astronomers who first captured and are now monitoring Ansky’s behavior are now considering other scenarios. For instance, the disc could be formed by gas captured by the flares that would be coming from shocks in the disc, caused by a small celestial object repeatedly traveling through — thus disrupting the orbiting material.
Brighter, Longer Bursts
There are other clues that Ansky’s bursts aren’t produced by conventionally understood forces. Ansky’s periodic X-ray bursts last 10 times longer and shine 10 times brighter than a typical QPE.
“For QPEs, we’re still at the point where we have more models than data, and we need more observations to understand what's happening,” Erwan Quintin, a European Space Agency research fellow and an author of the study, said in a press release. “We thought that QPEs were the result of small celestial objects being captured by much larger ones and spiraling down towards them. Ansky’s eruptions seem to be telling us a different story.”
Astronomers will try to better understand that story by watching the rare phenomenon unfold. Future ESA missions may also help the astronomers learn more about the gravitational waves associated with the X-ray bursts.
Read More: Here’s What Would Happen If You Walked Through a Black Hole
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Nature Astronomy. Discovery of extreme quasi-periodic eruptions in a newly accreting massive black hole
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
