Astronomers Discover Huge Black Hole in Our Cosmic Backyard

by Caitlin Berard
(Photo by Cappan via Getty Images)

What’s your biggest fear? Fear of the unknown has to at least crack the top five. The things we fear most all tend to fall into this category: the deep sea, the fathomless expanse of space, even death. It’s natural to be afraid of things we can’t fully conceptualize. And if the unknown is among the biggest driving forces behind fear, black holes are the most fearsome thing in existence.

Black holes are so mysterious, in fact, that it’s impossible to observe them directly with telescopes, even for NASA. Capable of devouring asteroids, stars, and planets whole, black holes form when large stars reach the end of their lifespans and collapse. The star’s death causes a supernova (a monstrous explosion) and the remnants become so dense that not even light can escape its gravitational pull.

Because of this, astronomers often study black holes by observing their effect on other objects rather than the chasmic leviathan itself. Now, if all that wasn’t terrifying enough, it gets worse.

Astronomers Discover Black Hole ‘Practically in Our Backyard’

In a recent study conducted by the University of Alabama Huntsville, astronomers found one of these cosmic bottomless pits in our backyard. The colossal black hole is twelve times the size of our Sun and is located only about 1,500 light-years from Earth.

While this is enough to make anyone look to the sky in fear, it actually provides a unique opportunity for scientists. Because of its massive size and relatively close location, scientists can learn more about the laws of physics as well as galaxy formation and evolution.

That said, as Dr. Sukanya Chakrabari, the Department of Physics Chair at UAH, explained, there are still many unanswered questions. “It is not yet clear how these noninteracting black holes affect galactic dynamics in the Milky Way,” she said in a press release. “If they are numerous, they may well affect the formation of our galaxy and its internal dynamics.”

“We searched for objects that were reported to have large companion masses but whose brightness could be attributed to a single visible star. Thus, you have a good reason to think that the companion is dark.”

How Scientists Found the Massive Exploded Star

To find the black hole, Dr. Chakrabarti and her team used data from the Gaia DR3, a data release containing new details for almost two billion stars in our galaxy. Among these were nearly 200,000 binary stars, consisting of a black hole and a visible star.

“The pull of the black hole on the visible Sun-like star can be determined from these spectroscopic measurements, which give us a line-of-sight velocity due to a Doppler shift,” Chakrabari explained. “These spectroscopic measurements independently confirmed the Gaia solution that also indicated that this binary system is composed of a visible star that is orbiting a very massive object.”

By analyzing the motions of the visible star, scientists can infer details about the accompanying black hole. “The majority of black holes in binary systems are in X-ray binaries,” Dr. Cahkrabari said. “In other words, they are bright in X-rays due to some interaction with the black hole, often due to the black hole devouring the other star.”

“As the stuff from the other star falls down this deep gravitational potential well, we can see X-rays,” she continued. “In this case, we’re looking at a monster black hole, but it’s on a long-period orbit of 185 days, or about half a year. It’s pretty far from the visible star and not making any advances toward it.”