What Is A Black Hole?
What is a black hole?
There are many strange and wonderful phenomenon being discovered throughout our Universe. One of the most intriguing is the concept of a black hole in space. Astronomers have discovered a black hole just 1,600 light years away from Earth. The National Radio Astronomy Observatory cataloged this black hole in the constellation Sagittari on a star called V4641.
Just what is a black hole? A black hole is theoretically, one form of a "dead" star. A star dies by shrinking until it is a white dwarf, about the size of the earth, or by shrinking until it is a neutron star, about 20 miles across. Neutron stars have a huge density, about a million tons per square inch. The concept holds that if a star continues to shrink it becomes a point in space with an infinite density—a black hole.
The singularity of the black hole is the center. Black holes suck in everything within a certain distance from their center. That distance is called the event horizon. Anything inside the event horizon would enter the black hole. Planets and stars are outside the event horizon and will not enter a black hole. They will, however, orbit it just as planets in our galaxy orbit the sun.
German astronomer Karl Schwarzschild developed the black hole concept in 1916. He based his concept on Albert Einstein's theory of relativity. Scientists had no proof that black holes existed until 1994, when the Hubble Space Telescope uncovered the first convincing evidence that black holes exist in Galaxy M87. Second and third black holes were discovered in 1995 in Galaxy NGC 4258 and NGC 4261.