page_title: Sagittarius A
section_title: Sagittarius A*
hierarchical_section_title: Sagittarius A / Sagittarius A*
caption_attribution_description: English: This image, not unlike a pointillist painting, shows the star-studded centre of the Milky Way towards the constellation of Sagittarius. The crowded centre of our galaxy contains numerous complex and mysterious objects that are usually hidden at optical wavelengths by clouds of dust — but many are visible here in these infrared observations from Hubble. However, the most famous cosmic object in this image still remains invisible: the monster at our galaxy’s heart called Sagittarius A*. Astronomers have observed stars spinning around this supermassive black hole (located right in the centre of the image), and the black hole consuming clouds of dust as it affects its environment with its enormous gravitational pull. Infrared observations can pierce through thick obscuring material to reveal information that is usually hidden to the optical observer. This is the best infrared image of this region ever taken with Hubble, and uses infrared archive data from Hubble’s Wide Field Camera 3, taken in September 2011. It was posted to Flickr by Gabriel Brammer, a fellow at the European Southern Observatory based in Chile. He is also an ESO photo ambassador.
context_page_description: Sagittarius A or Sgr A is a complex radio source at the center of the Milky Way which contains a supermassive black hole. It is located in the constellation Sagittarius, and is hidden from view at optical wavelengths by large clouds of cosmic dust in the spiral arms of the Milky Way.
  It consists of three components, the supernova remnant Sagittarius A East, the spiral structure Sagittarius A West, and a very bright compact radio source at the center of the spiral, Sagittarius A*. These three overlap: Sagittarius A East is the largest, West appears off-center within East, and A* is at the center of West.
context_section_description: Astronomers now have evidence there is a supermassive black hole at the center of the galaxy. Sagittarius A* (abbreviated Sgr A*) is agreed to be the most plausible candidate for the location of this supermassive black hole. The Very Large Telescope and Keck Telescope detected stars orbiting Sgr A* at speeds greater than that of any other stars in the galaxy. One star, designated S2, was calculated to orbit Sgr A* at speeds of over 5,000 kilometers per second at its closest approach.
  A gas cloud, G2, passed through the Sagittarius A* region in 2014 and managed to do so without disappearing beyond the event horizon as theorists predicted would happen. Rather, it disintegrated, suggesting the gas cloud G2 and previous gas cloud G1, were star remnants with larger gravitation fields than gas clouds.
  In September 2019, scientists found that Sagittarius A* had been consuming nearby matter at a much faster rate than usual over the past year. Researchers speculated that this could mean that the black hole is entering a new phase, or that Sagittarius A* had stripped the outer layer of G2 when it passed through.
caption: Astronomers have observed stars spinning around the  supermassive black hole in Sagittarius A*.[3]
exif: {"Image ImageDescription": "This image, not unlike a pointillist painting, shows the star-studded centre of the Milky Way towards the constellation of Sagittarius. The crowded centre of our galaxy contains numerous complex and mysterious objects that are usually hidden at optical wavelengths by clouds of dust \u2014 but many are visible here in these infrared observations from Hubble. However, the most famous cosmic object in this image still remains invisible: the monster at our galaxy\u2019s heart called Sagittarius A*. Astronomers have observed stars spinning around this supermassive black hole (located right in the centre of the image), and the black hole consuming clouds of dust as it affects its environment with its enormous gravitational pull. Infrared observations can pierce through thick obscuring material to reveal information that is usually hidden to the optical observer. This is the best infrared image of this region ever taken with Hubble, and uses infrared archive data from Hubble\u2019s Wide Field Camera 3, taken in September 2011. It was posted to Flickr by Gabriel Brammer, a fellow at the European Southern Observatory based in Chile. He is also an ESO photo ambassador."}