What is a Black Hole?
A black hole is an area of space with a gravitational hold that attaches itself to anything nearby. Astronomers believe that they occur when gravity collapses and leaves behind pockets shaped like a combination of a sphere and an elliptical. The gravitation force inside a black hole ensures that anything that enters this space cannot escape, including both light and stars. Some scientists believe that black holes defy the physics laws found on the Earth. They often believe that time moves at a different pace in a black hole too than it does in other parts of the universe.
History of Black Holes
Maarten Schmidt was the first person in history to identify what we now know is a black hole. While working in the 1960s, he spotted something that he thought was a star but noted that it was different from others. Astronomers working at the same time as Schmidt identified quasars and elliptical galaxies but found that most had a nucleus that was larger than any other star. In 1971, two men working in the United States theorized that the center of the Milky Way might contain a black hole. It wasn’t until the Hubble Space Telescope launched that astronomers could take photos of a black hole.
What Causes a Black Hole?
Though astronomers believe that black holes are related to gravitation forces and collapses, they have different theories on how these holes form. Some think that black holes form when massive stars explode and leave behind solar masses in the universe. Those masses eventually come together to form a black hole. Another theory claims that gas clouds would collect to form massive stars. Any of the gas left behind after the star formed the basis of a black hole. There is some evidence that black holes can grow and expand too.
What is the Largest Black Hole in the Universe?
The largest black hole in the Milky Way is one that astronomers call Sagittarius A+. They believe that it sits at or near the center of the Milky Way and that it’s roughly 26,000 light-years away from the Earth and other planets in our solar system. Their measurements found that it has an elliptical orbit and that the star called S2 follows that orbit. It is roughly 8.2×1036 kg in size also. NASA found a bright light coming from the black hole in 2015, which they believe was an x-ray flare caused by the hole absorbing a falling asteroid.
Outside of the Milky Way is a supermassive black hole that is part of the NGC 1277 galaxy. Astronomers believe that this black hole is 250 million light-years away from our planet and that it could fit 17 of our suns inside it. When astronomers first measured the black hole, they thought they made a mistake because they didn’t believe it could be that large. This black hole is 11 times larger than the orbit of Neptune around the Sun. That’s big! There is some evidence to show that at least five galaxies near NGC 1277 have black holes that are potentially just as large as this one.
Though astronomers found proof of a supermassive black hole at or near the centre of our Galaxy, the discovery of a supermassive black hole in the NGC 1277 galaxy in 2012 is potentially the largest black hole in our universe. This black hole is the same as those found in other galaxies in terms of what it does, but is larger than those holes. The largest black hole in our Galaxy is Sagittarius A+, which dwarfs those you might see in sci-fi films or read about in your favorite books.