1/22/2024 0 Comments Electron capture![]() Potential electron-capture supernovas have been reported before, but the evidence wasn’t definitive. “The big question here was, ‘Does this kind of supernova even exist?’” says astrophysicist Daichi Hiramatsu of the University of California, Santa Barbara and Las Cumbres Observatory in Goleta, Calif. If the star’s core gives way - boom - that sets off an electron-capture supernova.īut without an observation of such a blast, it remained theoretical. But if reactions within a star chip away at the number of electrons, that support weakens. Those zippy electrons exert a pressure that opposes the inward pull of gravity. That electron capture spells bad news for the star in its war against gravity because those electrons are helping the star fight collapse.Īccording to quantum physics, when electrons are packed closely together, they start moving faster. In this reaction, an electron vanishes as a proton converts to a neutron, and the nucleus morphs into another element. For some stars that fall in that range, scientists have long suspected that electron-capture supernovas should occur.ĭuring this type of explosion, neon and magnesium nuclei within a star’s core capture electrons. But between about eight and 10 solar masses, there’s a poorly understood middle ground for stars. Smaller stars, with less than about eight solar masses, are able to resist collapse, instead forming a dense object called a white dwarf ( SN: 6/30/21). The core collapses inward and then rebounds, causing the star’s outer layers to explode outward ( SN: 2/8/17). ![]() Stars with more than about 10 times the sun’s mass go supernova after nuclear fusion reactions within the core cease, and the star can no longer support itself against gravity. “These have been theorized for so long, and it’s really nice that we’ve actually seen one now,” says astrophysicist Carolyn Doherty of Konkoly Observatory in Budapest, who was not involved with the research.Įlectron-capture supernovas result from stars that sit right on the precipice of exploding. A flare that appeared in the sky in 2018, called supernova 2018zd, matches several expected hallmarks of the blasts, scientists report June 28 in Nature Astronomy. ![]() The phenomenon was first predicted in 1980, but scientists have never been sure that they have seen one. Researchers have found convincing evidence for an electron-capture supernova, a stellar explosion ignited when atomic nuclei sop up electrons within a star’s core. A long-predicted type of cosmic explosion has finally burst onto the scene. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |