{"id":28864,"date":"2022-02-10T00:00:00","date_gmt":"2022-02-10T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=28864"},"modified":"2022-03-23T13:14:07","modified_gmt":"2022-03-23T13:14:07","slug":"milky-ways-black-hole-reveals-erratic-nature","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/02\/10\/milky-ways-black-hole-reveals-erratic-nature\/","title":{"rendered":"Milky Way\u2019s black hole reveals erratic nature"},"content":{"rendered":"\n

Bright bursts from Sagittarius A* have waxed and waned for years<\/p>\n\n

\"\"
An image of our Galaxy\u2019s core made from X-ray observations by the Swift Observatory from 2006-13, with Sagittarius A* at its centre <\/figcaption><\/figure>\n\n

The black hole <\/strong>at the heart of the Milky Way erupts unpredictably and chaotically, a new study looking at over 15 years of data has found.<\/p>\n\n

Known as Sagittarius A* (Sgr A*), the black hole at the centre of our Galaxy lies more than 26,000 lightyears from Earth, and is around four million times the mass of the Sun. The hot gas and dust around the black hole means it glows brightly at radio, X-ray and gamma ray wavelengths. Astronomers have known for decades that over the timescale of a day the emissions will suddenly flare, increasing in brightness by ten to a hundred times, but weren\u2019t sure how this flaring behaved over longer time spans.<\/p>\n\n

To investigate this, Alexis Andr\u00e9s, a postgraduate student from the University of Amsterdam, looked at data taken by the Neil Gehrels Swift Observatory, a telescope which has been looking for gamma ray bursts since 2006.<\/span><\/p>\n\n

\u201cThe long dataset of the Swift Observatory did not just happen by accident,\u201d says Nathalie Degenaar, who requested the specific measurements from Swift when she was a PhD student and became Andr\u00e9s\u2019s supervisor at the University of Amsterdam. \u201cSince then, I\u2019ve been applying for more observing time regularly. It\u2019s a very special observing programme that allows us to conduct a lot of research.\u201d<\/p>\n\n

This data showed that Sgr A* had a high rate of flares from 2006 to 2008, which then dropped off before rising once again in 2012.<\/span><\/p>\n\n

\u201cHow the flares occur remains unclear,\u201d says Jakob van den Eijnden from the University of Oxford. \u201cIt was previously thought that more flares follow after gaseous clouds or stars pass by the black hole, but there is no evidence for that yet. And we cannot yet confirm the hypothesis that the magnetic properties of the surrounding gas play a role either.\u201d<\/p>\n\n

The team hope to uncover more about the flare\u2019s changing rate by monitoring Sgr A* using Swift over the next few years. This should reveal whether a passing cloud or an as yet unknown phenomenon is causing this fitful behaviour at our Galaxy\u2019s heart. https:\/\/swift.gsfc.nasa.gov\/<\/a><\/p>\n\n

Photos: NASA\/SWIFT\/N. DEGENAAR, NASA\/CALTECH-JPL\/MSSS, CFA\/LEAH HUSTAK (STSCI), MARK MYERS\/ARC CENTRE OF EXCELLENCE FOR GRAVITATIONAL WAVE DISCOVERY (OZGRAV)<\/p>\n","protected":false},"excerpt":{"rendered":"

Bright bursts from Sagittarius A* have waxed and waned for years<\/p>\n","protected":false},"author":24,"featured_media":28863,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"12","purple_custom_meta_purple_page_number":"12","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_12-1.xml","purple_custom_meta_purple_source_article":"article_12-1.xml","purple_source_issue":"March-2022","purple_custom_meta_purple_source_issue":"March-2022","purple_external_id":"March-2022-12-1","purple_custom_meta_purple_external_id":"March-2022-12-1","purple_issue_code":"|0000086550||","purple_custom_meta_purple_issue_code":"|0000086550||","purple_android_product":"com.im.skyatnight.202","purple_custom_meta_purple_android_product":"com.im.skyatnight.202","purple_ios_product":"com.im.skyatnight.202","purple_custom_meta_purple_ios_product":"com.im.skyatnight.202","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[19],"tags":[14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"2","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503.jpg",1982,1162,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503-300x176.jpg",300,176,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503-768x450.jpg",768,450,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503-1024x600.jpg",800,469,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503-1536x901.jpg",1536,901,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/02\/80966780-dca1-492e-ab5d-4bbb047b4503.jpg",1982,1162,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"Bright bursts from Sagittarius A* have waxed and waned for years","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/28864"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=28864"}],"version-history":[{"count":4,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/28864\/revisions"}],"predecessor-version":[{"id":29799,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/28864\/revisions\/29799"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/28863"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=28864"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=28864"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=28864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}