The newfound black hole is part of LB-1, a star-black-hole binary system located some 13,800 light-years away in the constellation of Gemini.
The more common stellar black holes - up to 20 times more massive than the Sun - form when the center of a very big star collapses in on itself.
"Sunless holes of such mass must no longer ever even exist in our galaxy, in response to most of primarily the latest units of stellar evolution", said Liu Jifeng, head of the team that made the discovery.
"Therefore, they should not let such remains solid", he continues.
The study suggests some potential explanations, including the "exciting possibility" that LB-1 might actually consist of two black holes orbiting each other, though Bregman said that would be rare.
Astronomers have stumbled across a black hole that is so damn large that they are perplexed at how it even exists.
This alternative formation is theoretically possible, but scientists have never been able to prove or observe it.
The black hole is 70 times more massive than the sun, the scientists wrote in a new study.
After finding the star, which they named LB-1, the researchers used two huge optical telescopes - the Gran Telescopio Canarias in La Palma, Spain, and the Keck I telescope in Hawaii - to determine the mass of the star and its black hole companion.
It is believed that stellar black holes are commonly dispersed throughout the universe, but they are hard to detect because they normally do not emit X-rays, they only do so when they engulf gas from a star that has ventured close enough.
But LAMOST, constructed between 2001 and 2008 in north China's Hebei province, allows researchers to detect up to 4,000 stars simultaneously with each exposure, making it one of the world's most powerful ground-based telescopes.
Some stellar black holes are detectable when they swallow gas from a companion star.
This leaves the theorists to explain what caused this kind of formation in the first place.
The hole has a mass 70 occasions that of the solar, researchers acknowledged of their stumble on published within the journal Nature.
The black hole in question was spotted in galaxy Messier 87 (M87) that is 55 million light-years away. As an different of looking to search out X-rays emitted by black holes, the team searched for stars that had been orbiting some invisible object, being pulled in by its gravity. These twin discoveries, the collision, and now LB-1 - indicates that scientists are reaching "a revival in our understanding of black hole astrophysics", Reitze said in the press release.
Out of the 100 million black holes believed to exist in our galaxy, Liu said, only 4,000 "can give you X-rays that can be detected by us".
As stated before, last April, scientists found the first-ever picture of a black hole, which was captured by the Event Horizon Telescope (EHT).this is an worldwide project that connected dozens of observatories in order to capture the first-ever image of a black hole.