Previous studies have shown that if a neutron star were above 2.5 times the mass of the Sun, it would collapse into a black hole.
That's because black holes are the corpses of what used to be massive stars that underwent an explosive demise, ultimately collapsing in on themselves.
'It opens up a new area of study'. According to the scientist, mini black holes are real.
"What we've done here is come up with a new way to search for black holes, but we've also potentially identified one of the first of a new class of low-mass black holes that astronomers hadn't previously known about".
"We're pretty sure that there must be many, many of these [mini black holes] in binary systems with stars out there in the galaxies, just that we haven't found them because they're hard to find".
The most massive neutron star that scientists know of is 2.1 times the mass of our sun, whereas the least massive black hole known is about five to six times the mass of our sun, Thompson said. But what about those that were smaller, existing between the boundary of neutron stars and black holes?
But if astronomers only focus on supermassive black holes, like the one at the center of our galaxy, and neutron stars, they're missing whole demographics of the population, the researchers said. On examining it further the researchers calculated a probable black hole having 3.3 solar masses. They looked at a binary star system which is made of the star 2MASS J05215658+4359220 and its companion. Their finding, in addition to sharing a novel way to search for black holes, published Thursday in the journal Science. But in order to uncover that information, astronomers first have to figure out where the black holes are.
Black holes often exist in something called a binary system, meaning that two stars are close enough to one another to be locked together by gravity in a mutual orbit around one another. In other words, the aforementioned tiny black hole may be one of these fabled quiescent black holes. "It's always interesting to try to find things that can't be seen", explained Todd Thompson, from The Ohio State University, for Live Science.
While narrowing down the list of stars to the most likely candidates, Thompson and his colleagues found a giant red star orbiting something smaller than the smallest known black hole but larger than any known neutron star. However, LIGO's discovery proved that black holes could be larger.
For long, black holes were estimated to exist in two ranges of size. The other star remains in place, orbiting the space where the dead star once was. He and other scientists began combing through data from APOGEE, the Apache Point Observatory Galactic Evolution Experiment, which collected light spectra from around 100,000 stars across the Milky Way. They were observing the changes in light from stars that may indicate that they are orbiting around some unseen object. This indicates the presence of a black hole that is not now consuming any material.
He narrowed the APOGEE data to 200 stars and gave the data to a graduate research associate at Ohio State, Tharindu Jayasinghe. Thompson said. "The masses of things tell us about their formation and evolution, and they tell us about their nature".
Black holes are some of the strangest and most fascinating objects in outer space.