Astronomers have made two discoveries after discovering a new type of black hole that is closer to Earth than scientists previously knew, According to the European Space Agency.
The two black holes, about ten times more massive than our planet’s Sun, were discovered by a team of scientists, led by Karim El-Badri, who observed their companion stars orbiting the massive object, ESA said in a March 30 statement.
The discovery of Gaia BH1 and Gaia BH2 very close to Earth (only 1,560 light-years away) suggests that “many more similar black holes in massive binaries still await discovery.”
“In galactic terms, these black holes reside in our cosmic backyard,” the agency’s statement said.
“True black” masses have the most widely separated orbits of all known black holes, possibly making them completely invisible, detectable only by their gravitational effects.
Until recently, all known black holes were detected by the emission of light, which distinguishes this new group of “practically invisible” black holes. Previously discovered black holes emitted light at radio and X-ray wavelengths – produced by material trapped within them.
“New findings suggest black holes are more common in massive binaries.”
How do they know it’s a black hole?
Using data from ESA’s Gaia mission, Astronomers measured the positions and motions of billions of stars to discover black holes and rule out other theories about what the mass orbiting these stars might be.
By observing their motion against the sky, astronomers can gain essential insights into the objects that gravitationally influence these stars, including other stars, exoplanets, and black holes.
“Black holes are detected by spotting tiny wobbles of their companion stars as they orbit them,” said Timo Prusti, ESA’s Gaia project scientist. “No other instrument (Gaia) is capable of such measurements.”
Additional measurements from ground-based observatories provided conclusive evidence that astronomers had indeed detected a black hole.
In 2022, Gaia released the first results from its stellar survey of more than 813,000 binary star systems, providing accurate measurements that led to the discovery of these two black holes. Astronomers will continue to gather information about where these black holes come from in wide orbits.
Gaia’s next data release in 2025 – based on 66 months of observations – will have more accurate information about the star’s orbit.
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Camille Fine is a trending visuals producer on USA TODAY’s NOW team.
