Astronomers announced on Friday, November 4, 2022 that they have discovered the closest known black hole to Earth. Not to worry, however, this black hole is dormant currently, meaning it’s not gravitationally consuming nearby stars, and is not a threat to our Earth. It’s located about 1,600 light-years away from Earth in the constellation Ophiuchus. The previous record-holder of the closest black hole to Earth is located in the constellation Monoceros, approximately 3,000 light years away. This newly discovered black hole is about 3 times closer to Earth than the black hole located in Monoceros, which astronomically is significantly nearer.
Black holes are celestial objects that are so dense that not even light can escape them. Small black holes are thought to originate from collapsed stars and it is estimated that we likely have millions of smaller black holes in our Milky Way. However, this newly identified black hole is to be categorized as a stellar-mass black hole. A stellar-mass black hole is estimated to weigh about 5 to 100 times the mass of our Sun, with our Sun being 1.989 ✕ 1030 kg. Although only a handful of them have been confirmed to exist, these massive black holes are estimated to be much more common than we perceive. There are most likely stellar-mass black holes at the center of large galaxies but we are still unsure on how or why they appear. The growth of black holes may be due to the their incredible diet that consists of eating light, but that may be a topic astronomers will have to investigate further!
The discovery of this black hole originated by observations of a similar Sun-like star. Kareem El-Badry, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, was the one credited for discovering this dormant black hole. He had been searching for proof of black holes like this one for about four years. He had been analyzing data from the European Space Agency’s GAIA spacecraft which has been tracking the position and motions of millions of stars all across the Milky Way. He found a star almost identical to our Sun that had obscure movement. By using the Gemini North telescope at Mauna Kea, Hawaii to investigate further, he was able to deduce that this Sun-like star was orbiting this black hole. Because of the process leading up to the discovery, they named this black hole the “Gaia BH1.” Gaia BH1 is estimated to weigh about 10 times the mass of our Sun and is said to be almost the exact distance away from its Sun-like star, as our Sun is to Earth.
The discovery of this stellar-mass black hole is a significant contribution for the astronomy field as this is the first proof that a system like this exists. There have been many claims that similar black hole systems to this one reside in our universe, but the majority of them have been disproven. Because this black hole is dormant, it makes it very hard to detect as it blends in with its surroundings very well, making Kareem El-Badry’s discovery more impressive. It does create the question of how many other black holes are similar to this one and could they be even larger?
KEIRA MEI HARRELL
My name is Keira Mei, I’m an 11th grader at City this year. I went to John Ball Zoo School in 6th grade and have been going to City ever since. I play the cello and also enjoy playing piano in my free time.