Astronomers believe they just bore witness to a supermassive black hole<\/a>, the sleeping giant at its galactic center<\/a>, awakening. Previously, no one had seen a black hole rousing as it was happening.\u00a0<\/p>\n “Imagine you\u2019ve been observing a distant galaxy for years, and it always seemed calm and inactive,” said Paula S\u00e1nchez S\u00e1ez, an astronomer at the European Southern Observatory, in a statement. “Suddenly, its [core] starts showing dramatic changes in brightness, unlike any typical events we’ve seen before.”<\/p>\n Astronomers are accustomed to observing individual stars suddenly brighten or dim<\/a>. Other galaxies have even been known to have brief flare-ups after a supernova<\/a> or a black hole within it ate a star<\/a>, but those episodes usually only last for a few days or months. Seeing an entire galaxy light up, then remain lit for many years after, is unprecedented, according to a team of scientists observing it with several ground and space telescopes, including NASA<\/a>‘s Swift and Chandra X-ray observatories.\u00a0<\/p>\n SEE ALSO: <\/a><\/p>\n S\u00e1nchez S\u00e1ez is the lead author of the new findings<\/a>, which appear in the Astronomy & Astrophysics journal.\u00a0<\/p>\n Black holes are some of the most inscrutable phenomena in the universe. They don’t have surfaces, like a planet or star. Instead, they have a boundary called an “event horizon<\/a>,” or a point of no return. If anything swoops too close, it will fall in, never to escape the hole’s gravitational clutch.<\/p>\n \n Mashable Light Speed\n <\/p>\n The most common, called stellar black holes<\/a>, are thought to be the result of enormous stars dying in supernova explosions. The stars then collapse onto themselves, their material condensing into relatively tiny areas.\u00a0<\/p>\n “These giant monsters usually are sleeping and not directly visible.”<\/p>\n But how supermassive black holes<\/a>, millions to billions of times more massive than the sun, form is even more elusive. Many astrophysicists and cosmologists believe these invisible giants lurk at the center of virtually all galaxies. Recent Hubble Space Telescope observations have bolstered the theory<\/a> that supermassive black holes begin in the dusty cores of starburst galaxies, where new stars are rapidly assembled, but scientists are still teasing that out.\u00a0<\/p>\n \n An artist’s conception of a black hole at the center of a distant galaxy brightening in two images, with ‘before’ on top and ‘after’ on bottom. To better understand SDSS1335+0728’s increased brightness, the team looked at archival data and new observations of the galaxy before and after the sudden change in December 2019. Not only did they find the galaxy, within the constellation Virgo, giving off more light at ultraviolet, optical, and infrared wavelengths, but it has even begun radiating in X-rays since this February.\u00a0<\/p>\n “These giant monsters usually are sleeping and not directly visible,” said co-author Claudio Ricci of the Diego Portales University in Chile in a statement. “In the case of SDSS1335+0728, we were able to observe the awakening of the massive black hole, [which] suddenly started to feast on gas available in its surroundings, becoming very bright.”<\/p>\n The team plans to continue its research and rule out other potential explanations. Some have suggested the brightening of the galaxy could be the result of an abnormally long tidal disruption event, which happens when a star strays too close to a black hole, and is violently shredded. Or perhaps the cause is some other never-before-documented phenomenon waiting to be discovered.<\/p>\n \n The first image of Sagittarius A*, the black hole at the center of the Milky Way galaxy.
\n
\n This nova is on the verge of exploding. You could see it any day now.<\/p>\n![\"Depicting](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/01\/images-1.fill.size_660x750.v1718651692.jpg\")
<\/p>\n
\n Credit: ESO \/ M. Kornmesser illustration\n <\/p>\n![\"Imaging](\"https:\/\/www.newsbeep.com\/nz\/wp-content\/uploads\/2026\/01\/images-2.fill.size_2000x1125.v1718651692.webp.webp\")
<\/p>\n
\n Credit: Event Horizon Telescope Collaboration\n <\/p>\n