Accordingly, the collapse of millions or billions of solar masses of interstellar gas under gravitational force into a large black hole would account for the enormous energy output of quasars and certain galactic systems. But these events are impossibly rare. It has about 15 times the mass of the Sun, and once again, it's in a binary system. We'll probably never know. These so-called mini black holes, like the more massive variety, lose mass over time through Hawking radiation and disappear. There are three different types of black hole. The crushing weight of constituent matter falling in from all sides compresses the dying star to a point of zero volume and infinite density called the singularity. Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree.... Black holes are formed when massive stars die. You know that saying, "keep your friends close, but keep your enemies closer?" The existence of another kind of nonstellar black hole was proposed by the British astrophysicist Stephen Hawking. And if you're close enough to see that, you're already dead. Stars with a smaller amount of mass evolve into less compressed bodies, either white dwarfs or neutron stars. We just don't know if the closest black holes is a few light years away, or it's actually V616 Mon. googletag.cmd.push(function() { googletag.display('div-gpt-ad-1449240174198-2'); }); We're talking regions of space where matter is compressed so densely that the only way to escape is to be traveling faster than the speed of light. One such supermassive black hole, Sagittarius A*, exists at the centre of the Milky Way Galaxy. By using our site, you acknowledge that you have read and understand our Privacy Policy The planets and even the Sun would be gobbled up, or smashed together, or even thrown out of the Solar System entirely. or, by Fraser Cain, Universe Today. 1817 views In 2017 the Event Horizon Telescope obtained an image of the supermassive black hole at the centre of the M87 galaxy. How do you find density in the ideal gas law. The size of the Schwarzschild radius is proportional to the mass of the collapsing star. Only the most massive stars—those of more than three solar masses—become black holes at the end of their lives. This article was most recently revised and updated by, https://www.britannica.com/science/black-hole, American Museum of Natural History - The Country Parson Who Conceived of Black Holes, black hole - Children's Encyclopedia (Ages 8-11), black hole - Student Encyclopedia (Ages 11 and up). We didn't encounter a black hole in billions of years, and probably won't encounter one for billions or trillions more years.