According to the European Space Agency, astronomers have found the greatest evidence yet for “intermediate-sized black holes.” They found a candidate in the nearest globular star cluster, 6,000 light years distant.
Most space-time black holes are tiny or huge. The Milky Way may include over 100 million tiny black holes. These black holes are several times the mass of our Sun.
The galaxy is full with “small” black holes, but the cosmos is full of supermassive black holes that weigh millions or billions of times our Sun. They’re usually in galaxies’ centers.
Like evolution, there is a missing link—an intermediate-mass black hole that weighs 100 to 100,000 times the Sun.
In 2020, Hubble found 3XMM J215022.4-055108, one of the two best intermediate-mass black holes. 2009’s HLX-1 is another contender. Both possibilities have tens of thousands of suns and live near other galaxies. ESA suggests these were dwarf galaxies’ centers.
Astronomers found a probable 800-solar-mass intermediate-mass black hole in the Monthly Notices of the Royal Astronomical Society. The astronomers computed the object’s mass by observing the stars in its gravitational field.
A black hole is the most likely explanation for this small, massive entity.
Astronomers resolved pinpoint stars from 12 years of Hubble scans of Messier 4 (M4). The European Space Agency’s Gaia probe scanned nearly 6,000 stars to restrict the cluster’s structure and mass.
“We believe we have a tiny region with a lot of concentrated mass. In a news statement, Eduardo Vitral, the study’s principal author, remarked, “It’s about three times smaller than the densest dark mass we had found before in other globular clusters.”
If the item is not an intermediate-mass black hole, it must be 40 smaller black holes packed into an area one-tenth of a light-year wide. If so, some may combine or be propelled outside the system.
“While we cannot prove it is a central point of gravity, we can demonstrate its smallness. It’s too little to explain beyond being a black hole. “Alternatively, there may be a stellar mechanism we don’t know about, at least within current physics,” said Vitral.