India’s AstroSat and NASA’s Space observatories capture dramatic eruptions from stellar wreckage around a massive black hole

India’s AstroSat and the National Aeronautics and Space Administration (NASA)’s Space observatories have captured dramatic eruptions from stellar wreckage around a massive black hole, the Indian Space Research Organisation (Isro) said in a statement on Thursday. It provides astronomers with valuable insights, linking two mysteries where there had previously only been hints of a connection.

A massive black hole has torn apart one star and is now using that stellar wreckage to pummel another star or smaller black hole that used to be in the clear. This discovery was made using NASA’s space observatories—Chandra, HST, NICER, Swift—and Isro’s AstroSat.

In 2019, astronomers witnessed the signal of a star that got too close to a black hole and was destroyed by the black hole’s gravitational forces. Once shredded, the star’s remains began circling the black hole in a disk in a type of stellar graveyard.

Over a few years, however, this disk has expanded outward and is now directly in the path of a star, or possibly a stellar mass black hole, orbiting the massive black hole at a previously safe distance. The orbiting star is now repeatedly crashing through the debris disk, about once every 48 hours, as it circles. When it does, the collision causes bursts of X-rays that astronomers captured with Chandra, Isro said.

“Imagine a diver repeatedly going into a pool and creating a splash every time she enters the water,” said Matt Nicholl of Queen’s University Belfast, United Kingdom, the lead author of the study that appears in the current issue of Nature. The paper describing these results was published by Nature in the October 9 issue of the journal.

“The star in this comparison is like the diver and the disk is the pool, and each time the star strikes the surface it creates a huge ‘splash’ of gas and X-rays. As the star orbits around the black hole, it does this over and over again,” he said.