Catching a supernova in action is tricky business. There is no way to predict them, and they don\u2019t occur very often. Within the Milky Way they only occur about once a century, and the last one was observed in 1604.<\/p>\n
<\/p>\n Of course, supernovae occur in other galaxies too, but you still have to get lucky to catch them as they explode.<\/p>\n But that\u2019s what happened last year, according to a new paper released in Nature<\/em> this week. Japanese amateur astronomer Koichi Itagaki, observing a nearby galaxy named Messier 101 (colloquially known as the Pinwheel Galaxy), recognized that something special was happening. He had just observed a new supernova. It was dubbed SN 2023ixf. <\/p>\n The initial phase of a supernova is measured in hours, so astronomers had to act fast. Within five hours, Itagaki had reported the sighting to an international astronomical reporting database called the Transient Name Server. Less than an hour after that, professional astronomers were already rushing to turn their telescopes to look at the new explosion.<\/p>\n The discovery took place on May 19, a Friday night, and it was a scramble to get everything in place across multiple time zones.<\/p>\n \u201cIt\u2019s very rare, as a scientist, that you have to act so swiftly,\u201d says Avishay Gal-Yam of the Weizmann Institute. \u201cMost scientific projects don\u2019t happen in the middle of the night, but the opportunity arose, and we had no choice but to respond accordingly.\u201d<\/p>\n Gal-Yam\u2019s PhD student and lead author of the paper, Erez Zimmerman, was part of the team who stayed up all night collecting data, and sharing information with the Hubble Space Telescope operators in time to make high-quality observations. Speed was of the essence.<\/p>\n \u201cThat\u2019s what makes this particular supernova different,\u201d says Zimmerman. \u201cWe were able \u2013 for the very first time \u2013 to closely follow a supernova while its light was emerging from the circumstellar material in which the exploding star was embedded.\u201d<\/p>\n The team had already applied for time on Hubble, intending to observe existing supernovae remnants in UV light. They got lucky in being able to observe a brand-new one instead. And even luckier that Hubble had just recently observed the same area, meaning that they not only captured the supernova in action, but also captured the star and its conditions in the days immediately before the explosion. These before-and-after observations are incredibly valuable in understanding the final days of a star\u2019s life.<\/p>\n \u201cStars behave very erratically in their senior years,\u201d says Gal-Yam. \u201cThey become unstable and we usually cannot be sure which complex processes occur within them because we always start the forensic process after the fact, when much of the data has already been lost.\u201d<\/p>\n Data from SN 2023ixf was also collected in X-ray from NASA\u2019s Swift spacecraft, and spectra were obtained from the ground-based Keck Observatory in Hawai\u2019i. Together, all these observations helped piece together the evolution of the explosion as it changed over time.<\/p>\n Another PhD student on the team, Ido Irani, says that the explosion probably formed a black hole, replacing the aged red giant that once sat in its place.<\/p>\n \u201cCalculations of the circumstellar material emitted in the explosion, as well as this material\u2019s density and mass before and after the supernova, create a discrepancy, which makes it very likely that the missing mass ended up in a black hole that was formed in the aftermath of the explosion \u2013 something that\u2019s usually very hard to determine,\u201d he says.<\/p>\n Follow-up observations are expected to provide even more details about the event, and help astronomers understand more precisely how supernovae occur and interact with their environment.<\/p>\n Learn More:<\/p>\n \u201cA Hundred Million Suns.\u201d Keck Observatory.<\/p>\n![\"\"](\"https:\/\/www.universetoday.com\/wp-content\/uploads\/2024\/03\/Keplers_supernova.jpg\")
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