{"id":34566,"date":"2018-10-31T11:56:19","date_gmt":"2018-10-31T06:26:19","guid":{"rendered":"https:\/\/blog.forumias.com\/?p=34566"},"modified":"2018-10-31T11:56:19","modified_gmt":"2018-10-31T06:26:19","slug":"observations-confirm-neutron-star-merger","status":"publish","type":"post","link":"https:\/\/forumias.com\/blog\/observations-confirm-neutron-star-merger\/","title":{"rendered":"Observations confirm neutron star merger:"},"content":{"rendered":"<p><a href=\"http:\/\/www.thehindu.com\/todays-paper\/tp-national\/observations-confirm-neutron-star-merger\/article19874039.ece\"><span style=\"font-weight: 400;\">Observations confirm neutron star merger<\/span><\/a><span style=\"font-weight: 400;\">:<\/span><\/p>\n<p><b>Context:<\/b><\/p>\n<p><span style=\"font-weight: 400;\">For the first time, a cosmic event has been observed with gravitational waves and also light waves.<\/span><\/p>\n<p><b>Introduction:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The<\/span><b> LIGO-VIRGO collaboration, <\/b><span style=\"font-weight: 400;\">three members of which won this year\u2019s physics Nobel Prize, detected the merger of two neutron stars \u2013extremely dense, massive but tiny, objects.<\/span><\/li>\n<\/ul>\n<p><b>Observations:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Gamma rays bursting from the event were observed by nearly 70 ground and space-based observations.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The second part of the discovery- the observation of Gamma ray bursts by several telescopes includes the observations by the <\/span><b>Giant Metreware Radio Telescope (GMRT), the Himalayan Chandra Telescope (HCT)<\/b><span style=\"font-weight: 400;\"> and <\/span><b>AstroSat.<\/b><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The CZTI instrument on AstroSat helped narrow down the location of the gamma-ray flashes.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Observations which were made earlier by LIGO have been of <\/span><b>black hole mergers, <\/b><span style=\"font-weight: 400;\">and as no light can escape from a black hole, there was no such light counterpart to the measurements.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The GMRT played a key role in understanding jet physics and refining models of radio emission from the remnant formed by the merging neutron stars.<\/span><\/li>\n<\/ul>\n<p><b>Importance of discovery:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Neutron-star mergers are incredibly rich and complex phenomena.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">E<\/span><span style=\"font-weight: 400;\">very \u00a0area of physics and astrophysics can learn something from this unique laboratory set up by nature.<\/span><\/li>\n<\/ul>\n<p><b>Outcomes of discovery:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The gravitational waves and the gamma ray burst, which light waves are arrived at nearly the same time indicate that the speed of gravitational waves is extremely close to the speed of light.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">This was predicted by Einstein, but it is the first time we are making a direct measurement.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The neutron stars of the signal detected were located about 130 million light years away.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">These neutron stars emitted gravitational waves that were detectable for about 100 seconds.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">When they collided, a flash of light in the form of gamma rays was emitted.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">This gamma rays burst was seen on Earth about two seconds after the gravitational wavers were observed.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The detection of a neutron star merger was surprising, because neutron stars are much smaller than black holes and their mergers produce much weaker gravitational waves than do black hole mergers.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The observations have given \u00a0astronomers \u00a0an unprecedented opportunity \u00a0\u00a0\u00a0\u00a0\u00a0<\/span> <span style=\"font-weight: 400;\">to probe a collision of two neutron stars<\/span><\/li>\n<\/ul>\n<p><b>Neutron stars:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">Neutron stars are the smallest, densest stars known to exist.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">These could be about 20 kilometres in diameter and have masses much greater than the Sun.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">A teaspoonful \u00a0of neutron star material could hold a mass of a billion tonnes.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">They are formed when massive stars explode in supernovae.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">As these neutron stars spiraled together, they emitted gravitational wave that were detectable for about 100 seconds, when they collided, a flash of light in the form of gamma rays was emitted and seen on Earth about two seconds after the gravitational waves.<\/span><\/li>\n<\/ul>\n<p><b>About LIGO:<\/b><\/p>\n<ul>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">The LIGO-VIRGO collaboration includes about 1,500 scientists and of this about 40 are Indians.<\/span><\/li>\n<li style=\"font-weight: 400;\"><span style=\"font-weight: 400;\">LIGO is the largest and most ambitious project ever funded by the NSF<\/span><span style=\"font-weight: 400;\">( National Science Foundation).<\/span><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Observations confirm neutron star merger: Context: For the first time, a cosmic event has been observed with gravitational waves and also light waves. Introduction: The LIGO-VIRGO collaboration, three members of which won this year\u2019s physics Nobel Prize, detected the merger of two neutron stars \u2013extremely dense, massive but tiny, objects. Observations: Gamma rays bursting from&hellip; <a class=\"more-link\" href=\"https:\/\/forumias.com\/blog\/observations-confirm-neutron-star-merger\/\">Continue reading <span class=\"screen-reader-text\">Observations confirm neutron star merger:<\/span><\/a><\/p>\n","protected":false},"author":61,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"footnotes":""},"categories":[555],"tags":[],"class_list":["post-34566","post","type-post","status-publish","format-standard","hentry","category-test-1","entry"],"jetpack_featured_media_url":"","views":{"total":0,"cached_at":"","cached_date":1704922072},"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/34566","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/users\/61"}],"replies":[{"embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/comments?post=34566"}],"version-history":[{"count":0,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/posts\/34566\/revisions"}],"wp:attachment":[{"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/media?parent=34566"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/categories?post=34566"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/forumias.com\/blog\/wp-json\/wp\/v2\/tags?post=34566"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}