NASA and ISRO's AstroSat capture a black hole ripping apart a star and now targeting another one

In 2019, scientists witnessed a star getting too close to a black hole. (Image: NASA/ISRO)

Astronomers have made an exciting discovery in space. A massive black hole has torn apart a star, using its remains to bombard another star or smaller black hole nearby. This breakthrough came from observations by NASA’s Chandra, Hubble, NICER, Swift, and ISRO’s AstroSat.

In 2019, scientists witnessed a star getting too close to a black hole. The black hole's strong gravitational forces shredded the star, leaving its remains in a disk. This disk has now expanded and is colliding with an orbiting star about every 48 hours.

Matt Nicholl from Queen’s University Belfast explained the phenomenon. He likened the orbiting star to a diver making a splash in a pool. Each time the star crashes into the debris, it creates bursts of X-rays.

Previously, astronomers have documented events where stars were destroyed by black holes. These “tidal disruption events” (TDEs) were single flashes of light. Recently, researchers discovered “quasi-periodic eruptions” (QPEs), which are repeating bursts of X-rays associated with supermassive black holes.

Co-author Dheeraj Pasham from MIT highlighted the significance of this finding. He said it provides proof of a connection between TDEs and QPEs. “It’s like solving two cosmic mysteries at once,” he noted.

Artist's impression of an orbiting star crashing through the accretion disk around a supermassive black hole and causing a burst of X-rays. (Image: NASA/ISRO)

The tidal disruption event, named AT2019qiz, was first spotted in 2019 by the Zwicky Transient Facility at the Palomar Observatory. Further observations in 2023 with Chandra and Hubble revealed insights into the debris disk.

Chandra’s observations showed weak signals, but a strong burst in the middle observation. Researchers then used NASA's NICER to monitor AT2019qiz for repeated X-ray bursts. They confirmed that these eruptions occur roughly every 48 hours.

The findings were published in the October 9 issue of Nature.

Additional observations from NASA's Swift Observatory and India’s AstroSat provided more evidence. The data from Hubble revealed the size of the debris disk. The findings indicate that any object orbiting the black hole closely could collide with the disk.

Gulab Dewangan from the Inter-University Center for Astronomy & Astrophysics noted AstroSat's unique capabilities. It detected AT2019qiz but observed eruptions only in X-rays. Future studies will improve understanding of these cosmic events.

Andrew Mummery from Oxford University remarked on this significant breakthrough. He stated that researchers need to wait a few years for eruptions to occur after a star is torn apart. It takes time for the disk to expand and interact with other stars.

This discovery may help astronomers find more QPEs linked to tidal disruptions. Identifying these events can help measure the prevalence of objects near supermassive black holes. Such targets may prove valuable for upcoming gravitational wave observatories.