Black hole taking bites from star discovered in nearby galaxy

(CN) — A black hole may be eating away at a sun-like star in a nearby galaxy, but it’s helping astronomers to further understand the interaction between black holes and orbiting stars.

Researchers from the University of Leicester in the U.K. documented the discovery of this ill-fated star in a galaxy around 500 million light years away in a study published Thursday in Nature Astronomy.

Astronomers first detected the star using a new transient hunting tool at Neil Gehrels Swift Observatory, a NASA space observatory with three telescopes that each monitor gamma ray bursts and the bursts’ X-ray and ultraviolet afterglow.

“This is the first time we’ve seen a star like our Sun being repeatedly shredded and consumed by a low mass black hole,” lead author Phil Evans of the University of Leicester School of Physics and Astronomy said in a statement.

The star, named Swift J0230 and orbiting a relatively small black hole, would emit an intermittent x-ray flash for 7-10 days and then switch off and on.

“So-called ‘repeated, partial tidal disruption’ events are themselves quite a new discovery and seem to fall into two types: those that outburst every few hours, and those that outburst every year or so," Evans said. “This new system falls right into the gap between these, and when you run the numbers, you find the types of objects involved fall nicely into place, too.”

Based on models for these types of outbursts, the researchers extrapolated the flash they were seeing came from a star similarly sized to our own sun that was orbiting a black hole at the center of its galaxy. As the star’s elliptical orbit took it close to the black hole, gravitational pull yanked three Earths’ worth of material from the star. Intense heat, around 2 million degrees Celsius, (3,600,032 degrees Fahrenheit) generated from the material as it fell into the black hole created by the X-ray flash that astronomers saw.

“In most of the systems we’ve seen in the past the star is completely destroyed. Swift J0230 is an exciting addition to the class of partially disrupted stars as it shows us that the two classes of these objects already found are really connected, with our new system giving us the missing link,” paper co-author Rob Eyles-Ferris said.

Swift J0230 is the first star being gradually consumed by a black hole that astronomers have discovered, but the study authors anticipate that the Swift Observatory’s recently enabled transient X-ray detector tool will continue to find more similar stars.

“This type of object was essentially undetectable until we built this new facility, and soon after it found this completely new, never-before-seen event,” Evans said. “Swift is nearly 20 years old and it’s suddenly finding brand new events that we never knew existed. I think it shows that every single time you find a new way of looking at space, you learn something new and find there’s something out there you didn’t know about before.”