Astronomers find closest black hole Nevertheless in’nearby’ star system


An artist’s impression depicts the orbits of 2 celebrities (in blue) and a stellar mass black hole (in red) in a triple system only 1,000 light years from Earth. . Picture: ESO/L. It’s the nearest known hole.
“We were totally amazed when we realised that this really is actually the first stellar system with a black hole which can be viewed with the unaided eye,” said Petr Hadrava, emeritus scientist at the Academy of Sciences of the Czech Republic in Prague and co-author of a study in the journal Astronomy & Astrophysics.
The star system, known as HR 6819, was seen as part of a study of binary star systems. Employing the FEROS spectrograph with the European Southern Observatory’s MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile, researchers were surprised to find among the visible stars, one having five or more times the mass of the sun, has been orbiting an unseen body every 40 days. The star is at a distance in the group.
Analysing the celebrity’s movement, the group concluded it is orbiting a black hole.
“This system includes the nearest black hole to Earth that we are aware of,” explained ESO scientist Thomas Rivinius, who led the analysis.
Only a few dozen stellar-mass black holes are found in the Milky Way to date. Most of them interact violently releasing bursts of detectable X-rays. But quiescent black holes could be a commonplace end state for stars across the world’s history.
“There must be countless millions of black holes out there, but we understand about just quite few,” explained Rivinius. “Knowing what to look for should put us in a better position to locate them.”