Scientists have discovered what may potentially be the Milky Way galaxy's smallest known black hole. Nicknamed 'the Unicorn', this black hole is potentially the closest one to our solar system.
According to Reuters, the researchers said the black hole is roughly three times the mass of our sun. Even though it is the closest one to us, it is still pretty far away from Earth as it is located at a distance of 1,500 light-years (the distance travelled by light in a year, 9.5 trillion km) from Earth.
Black holes like this one form when massive stars die and their cores collapse.
"We nicknamed this black hole 'the Unicorn' partly because V723 Mon is in the Monoceros constellation - which translates to unicorn - and partly because it is a very unique system" in terms of the black hole's mass and relative closeness to Earth, Ohio State University astronomy doctoral student Tharindu Jayasinghe, lead author of the study published this week in the journal Monthly Notices of the Royal Astronomical Society said to Reuters.
Black holes can be separated into three categories: The smallest ones are so-called stellar mass black holes. These are formed by the gravitational collapse of a single star. Secondly, there are the 'supermassive' black holes, like the one that stands at our galaxy's centre. 26,000 light-years from Earth, it is four million times the sun's mass. A few intermediate-mass black holes also have been found. Their masses range between that of the small and supermassive ones.
"'The unicorn' is truly one of the smallest black holes possible," Jayasinghe said.
The only potential black hole that can be smaller than the Unicorn is the one that was discovered in another galaxy. It has a mass 2.6 times that of the sun, Jayasinghe added.
Last year, a team of scientists described a black hole roughly 1,000 light-years from Earth. However, other researchers have questioned whether it qualifies as a black hole.