An artist's impression of the LB-1, a "monster" stellar black hole discovered by a Chinese-led research team.
A new discovery is blasting a hole in scientific theories about the Milky Way galaxy.
Experts have long believed the size of stellar black holes — dense cosmic bodies formed when massive stars explode and collapse — in our galaxy was no more than 20 times that of our sun.
But the discovery of a new “monster black hole” by a team of international scientists has crushed that estimation, according to a new study published in the latest issue of Nature.
A research team led by professor Liu Jifeng of the National Astronomical Observatory of China of the Chinese Academy of Sciences (NAOC) spotted a stellar black hole with a mass 70 times bigger than the sun.
“Black holes of such mass should not even exist in our galaxy, according to most of the current models of stellar evolution,” Jifeng said in a statement.
The “monster,” located 15,000 light-years from Earth, has been officially named LB-1 by the Chinese-led research team.
“We thought that very massive stars with the chemical composition typical of our galaxy must shed most of their gas in powerful stellar winds, as they approach the end of their life,” Jifeng said. “Therefore, they should not leave behind such a massive remnant. LB-1 is twice as massive as what we thought possible. Now theorists will have to take up the challenge of explaining its formation.”
Until recently, stellar black holes — the kind so dense light can’t escape them — were only discovered when they siphoned gas from a companion star, according to NASA. That process creates powerful X-ray emissions, detectable from Earth, that reveal the presence of the collapsed star.
However, most of these bodies “are not engaged in a cosmic banquet,” so only about two dozen galactic stellar black holes have been accurately identified and measured, the new study reported.
Jifeng’s researchers zeroed in on LB-1 with China’s Large Sky Area Multi-Object Fiber Spectroscopic Telescope, which looks for the “one out of a thousand stars” orbiting an invisible object’s gravitational pull.
After the initial discovery, the world’s largest optical telescopes — Spain’s 10.4-meter Gran Telescopio Canarias and the 10-meter Keck I telescope in the US — were used to pinpoint the system’s measurements.
The results were stunning: a star eight times heavier than the sun was spotted orbiting a “70-solar-mass black hole” every 79 days.
The discovery of LB-1 serves as a companion piece to another breakthrough in astrophysics, experts said.
Over the last four years, Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo gravitational wave detectors have started catching “ripples in spacetime” sparked by black hole collisions in galaxies far, far away.
The direct sighting of LB-1, however, proves that this population of “over-massive” stellar black holes exist in our very own Milky Way, said LIGO Director David Reitze, a physicist from the University of Florida.
“This discovery forces us to re-examine our models of how stellar-mass black holes form,” Reitze added. “This remarkable result … really points towards a renaissance in our understanding of black-hole astrophysics.”