S5-HVS1 is anA-type main-sequence star notable as the fastest one detected as of November 2019, and has been determined to be traveling at 1,755 km/s (3,930,000 mph), almost 0.6% of the speed of light.[1][3][4][5][6][7][8][9][10] The star is in theGrus (or Crane)constellation in the southern sky, and about 29,000light-years from Earth. According to astronomers, S5-HVS1 was ejected from theMilky Waygalaxy after interacting withSagittarius A*, thesupermassive black hole at the center of the galaxy.[1][3] It is possible that it was originally part of abinary system that was tidally disrupted by the supermassive black hole, causing it to be ejected. If this is the case, that it was flung out of the galaxy by the central black hole, it is then the first example of a star that has undergone theHills mechanism.
