About 500 million light-years away, an unfortunate star the size of our sun is being sucked into a tiny black hole every week – and astronomers stumbled upon the situation because they noticed the flashes of light that accompanied this event. These flashes of light appear to burst out as stellar material is devoured by the black hole, then shine brightly for seven to ten days before suddenly stopping, like flipping a switch. Nearly a month later, the black hole attacked the star again. First recorded in June 2022 by Neil Gehrels’ Swift Observatory space telescope, these observations show that the star, a white dwarf named Swift J0230, lost mass over time. but three times the mass of Earth every time it passes near the black hole. Astronomers call this process a tidal disruption event, of which only about 100 are known. Related: Black holes tear apart stars in a cosmic feeding frenzy that delights astronomers It is not unusual for stars to be only partially shredded by black holes in this way – previous research has shown that such half-deaths may be even more common than destructions – but the explosions in the past occurred every few hours or once a year. The team’s new observations provide a happy medium. “Swift J0230 is an exciting addition to the disrupted class of stars in part because it shows us that two classes of objects were found before,” said research collaborator Rob Eyles-Ferris. Those are really interconnected, and our new system provides us with the missing link.” at the University of Leicester in the United Kingdom, said in a statement. The team calls Swift J0230 an “accidental discovery” because previous observations from December 2021 to January 2022 did not detect the breakthrough event. After the initial detection in June, regular observations of Swift J0230 showed that the star’s brightness decreased rapidly on the fourth day. According to new research, this is when it declines by a factor of 20 in just 57 kiloseconds (15.8 hours). Soon after, the star became elusive to telescopic observations. The team’s best guess for Swift J0230’s location was near the galactic center, as expected since that’s where black holes typically reside. However, it should be noted that the suspected location of the star also coincides with the location of a Type II supernova discovered in 2020. Although the team did not completely rule out the possibility that what they observed was indeed a stellar explosion, “it is difficult to know how a supernova could have evolved into the object we detected.” out,” the researchers wrote in their new study.

X-ray image of the same location in the sky before (left) and after (right) the star named Swift J0230. (Image credit: Daniele B. Malesani / PanSTARRS) The black hole part of this equation lies at the center of a galaxy called 2MASX J02301709+2836050, a small galaxy about 10,000 to 100,000 times the mass of the surface. God. For comparison, the supermassive black hole at the center of our galaxy, the Milky Way, is more than 4 million times more massive than our sun, and many others hidden deep in space are about 100 million times more massive. amount of sun. . New research, which marks the first time a star the size of our sun has been chopped up, shows how relatively small black holes are hungry cosmic monsters. However, why this particular gap only partially disrupts the star is not very well understood. Much of the current research on breakthrough events focuses on the distance between a star and the black hole as the main factor determining the degree to which the star is fragmented. To learn more, another team of astronomers used supercomputers in 2021 to simulate the deformation of eight different types of stars as they approach a supermassive black hole.

Their results show that the initial density of stars is also a significant contributing factor and that partial disruptions play an “important but previously overlooked role” in the deaths of stars and can “shrink stars that were once massive before they were completely disrupted. Swift J0230 appears to have a similar fate. The research was described in a paper published in September. 7 in the journal Nature Astronomy.

source: https://www.nature.com/articles/s41550-023-02073-y