by In the center of our galaxy, hundreds of stars closely orbit a supermassive black hole. Most of these stars have large enough orbits that their motion is described by Newtonian gravity and Kepler's laws of motion.
But a few orbit so closely that their orbits can only be accurately described by Einstein's theory of general relativity. The star with the smallest orbit is known as S62. Its closest approach to the black hole has it moving more than 8% of light speed.
Our galaxy's supermassive black hole is known as Sagittarius A* (SgrA*). It is a mass of about 4 million suns, and we know this because of the stars that orbit it. For decades, astronomers have tracked the motion of these stars. By calculating their orbits, we can determine the mass of SgrA*.
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But a few orbit so closely that their orbits can only be accurately described by Einstein's theory of general relativity. The star with the smallest orbit is known as S62. Its closest approach to the black hole has it moving more than 8% of light speed.
Our galaxy's supermassive black hole is known as Sagittarius A* (SgrA*). It is a mass of about 4 million suns, and we know this because of the stars that orbit it. For decades, astronomers have tracked the motion of these stars. By calculating their orbits, we can determine the mass of SgrA*.
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