{"id":18187,"date":"2019-01-10T21:00:57","date_gmt":"2019-01-10T13:00:57","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/supernova-leftovers-preserve-evidence-of-a-messy-blowup-that-wrecked-two-stars\/"},"modified":"2019-01-10T21:00:57","modified_gmt":"2019-01-10T13:00:57","slug":"supernova-leftovers-preserve-evidence-of-a-messy-blowup-that-wrecked-two-stars","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/supernova-leftovers-preserve-evidence-of-a-messy-blowup-that-wrecked-two-stars\/","title":{"rendered":"Supernova leftovers preserve evidence of a messy blowup that wrecked two stars"},"content":{"rendered":"
\"Red
This artist\u2019s view shows a white dwarf star accumulating material from a nearby red giant star. Ultimately, the white dwarf erupts into a supernova. (Instituto de Astrof\u00edsica de Canaria Illustration \/ Romano Corradi)<\/figcaption><\/figure>\n

In what sounds like a cosmic episode of \u201cCSI,\u201d sleuthing astronomers have figured out what touched off a stellar explosion 545 million light-years away, based on evidence left behind at the scene of the crime.<\/p>\n

An international team of astronomers used the Hubble Space Telescope and other observatories to sift through the chemical fingerprints left behind in the remnants of a Type Ia supernova known as SN 2015cp. The astronomers knew the type of star that blew up: It was a carbon-oxygen white dwarf. But they wanted to find out whether a different kind of star had a hand in the blast.<\/p>\n

Today the astronomers reported the detection of hydrogen-rich debris in the vicinity of the supernova site \u2014 which cracks the case wide open.<\/p>\n

\u201cThe presence of debris means that the companion was either a red giant star or similar star that, prior to making its companion go supernova, had shed large amounts of material,\u201d University of Washington astronomer Melissa Graham said in a news release.<\/p>\n

Graham is the lead author of a paper on the findings accepted for publication in The Astrophysical Journal. She presented the team\u2019s results today at the American Astronomical Society\u2019s winter meeting.in Seattle.<\/p>\n

Type Ia supernovae are of special interest because they have a consistent luminosity, which makes them useful to astronomers as \u201cstandard candles\u201d to judge cosmic distances. Observations of such supernovae were key to the discovery in the late 1990s that the expansion of the universe is accelerating, due to a mysterious phenomenon known as dark energy.<\/p>\n

However, there\u2019s much that still isn\u2019t known about Type Ia supernovae.<\/p>\n

Astronomers think most of the stellar blowups are triggered by the interaction between two carbon-oxygen white dwarfs in a binary star system. Such stars are small, dense and tidy. In contrast, red giants are big and messy. If a red giant is paired with a white dwarf in a binary system, the hydrogen-rich material thrown off by the bigger star could fall onto the smaller one, eventually sparking an explosion.<\/p>\n

Figuring out the detailed mechanisms that trigger Type Ia supernovae is key to building astronomers\u2019 confidence in their use as standard cosmological candles.<\/p>\n

\u201cAll of the science to date that has been done using Type Ia supernovae \u2026 rests on the assumption that we know reasonably well what these \u2018cosmic lighthouses\u2019 are and how they work,\u201d Graham said. \u201cIt is very important to understand how these events are triggered, and whether only a subset of Type Ia events should be used for certain cosmology studies.\u201d<\/p>\n

To get a better understanding of the trigger mechanisms, Graham and her colleagues surveyed 70 Type Ia supernovae one to three years after their blowups. \u201cWe were searching for signs of shocked material that contained hydrogen, which would indicate that the companion was something other than another carbon-oxygen white dwarf,\u201d she said.<\/p>\n

The astronomers found what they were looking for in SN 2015cp, a supernova first detected in 2015. When Hubble made its observations in 2017, it picked up the ultraviolet glow of debris at least 62 billion miles (100 billion kilometers) away from the supernova source. Follow-up observations confirmed the presence of hydrogen.<\/p>\n

Based on the survey\u2019s results, the astronomers estimate that no more than 6 percent of Type Ia supernovae involve a messy red-giant companion. Graham said repeated observations of such supernovae should firm up those estimates.<\/p>\n

In addition to Graham, the authors of \u201cDelayed Circumstellar Interaction for Type Ia SN 2015cp Revealed by an HST Ultraviolet Imaging Survey\u201d include Chelsea Harris, Peter Nugent, Kate Maguire, Mark Sullivan, Mathew Smith, Stefano Valenti, Ariel Goobar, Ori Fox, Ken Shen, Tom Brink, Alex Filippenko, Patrick Kelly and Curtis McCully. The research was funded by the National Science Foundation, NASA, the European Research Council and the U.K.\u2019s Science and Technology Facilities Council.<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

This artist\u2019s view shows a white dwarf star accumulating material from a nearby red giant star. Ultimately, the white dwarf erupts into a supernova. (Instituto de Astrof\u00edsica de Canaria Illustration \/ Romano Corradi) In what sounds like a cosmic episode of \u201cCSI,\u201d sleuthing astronomers have figured out what touched off a stellar explosion 545 million […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[4393,1661,5084,4368],"class_list":["post-18187","post","type-post","status-publish","format-standard","hentry","category-news","tag-aas","tag-astronomy","tag-supernova","tag-university-of-washington"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/18187"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=18187"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/18187\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=18187"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=18187"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=18187"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}