Technically Sagittarius A*, the supermassive black hole at the centre of the Milky Way, is dormant. <\/p>
Black holes, although emitting no light of their own, interact with their environment because of their enormous gravitational fields. They usually form an accretion disc of material orbiting faster and faster as it is pulled towards the event horizon.<\/p>\n
Friction in the accretion disc<\/a> heats up the material and produces X-rays, which reveal the presence of the black hole<\/a> to astronomers. In many cases, the accretion disc, combined with strong magnetic fields, channels the flow of matter and energy away from the black hole, in powerful \u2018jets\u2019 that are at right angles to the disc.<\/p>\n If there is no material available to a black hole, then the accretion disc eventually dissipates. The black hole has stopped \u2018feeding\u2019 and there is no material producing X-rays. The black hole has become \u2018quiescent\u2019 or \u2018dormant\u2019 and the only way to detect its presence is through its gravitational effect on nearby objects.<\/p>\n The black hole may not be dormant forever. Other material\u00a0may eventually come into range of the black hole\u2019s influence and kick-start the process again. The black hole will become \u2018active\u2019 again.<\/p>\n Read more:<\/strong><\/p>\n Asked by: Eleanor Smith, via email<\/strong><\/p>\n To submit your questions email us at questions@sciencefocus.com (don\u2019t forget to include your name and location)<\/em><\/p> <\/body><\/html>\n Technically Sagittarius A*, the supermassive black hole at the centre of the Milky Way, is dormant. <\/p>\n","protected":false},"author":24,"featured_media":27523,"template":"","categories":[30],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss.jpg",1200,511,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss-300x128.jpg",300,128,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss-768x327.jpg",768,327,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss-1024x436.jpg",800,341,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss.jpg",1200,511,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/05\/sleeping-giants-how-dormant-black-holes-emerge-from-cosmic-abyss.jpg",1200,511,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"Technically Sagittarius A*, the supermassive black hole at the centre of the Milky Way, is dormant.","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed\/27522"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media\/27523"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media?parent=27522"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/categories?post=27522"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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