A star shredded by a black hole may have spit out an extremely energetic neutrino
A neutrino that plowed into the Antarctic ice offers up a cautionary message: Don’t stray too close to the edge of an abyss. The subatomic particle may have been blasted outward when a star was ripped to pieces during a close encounter with a black hole, physicists report May 11 at arXiv.org. If it holds up, the result would be the first direct evidence that such star-shredding events can accelerate subatomic particles to extreme energies. And it would mark only the second time that a high-energy neutrino has been traced back to its cosmic origins. With no electric charge and very little mass, neutrinos are known to blast across the cosmos at high energies. But scientists have yet to fully track down how the particles get so juiced up. One potential source of energetic neutrinos is what’s called a tidal disruption event. When a star gets too close to a supermassive black hole, gravitational forces pull the star apart (SN: 10/11/19). Some of the star’s...