A voracious black hole consumes the equivalent of three Earths’ worth of stars with each pass

A voracious black hole consumes the equivalent of three Earth stars every time it passes by. A star like our sun in a nearby galaxy is gradually eaten away by a small but voracious black hole, losing the mass equivalent of three Earths with each pass close.

The discovery by astronomers at the University of Leicester is reported in the journal Nature Astronomy and provides a “missing link” in our knowledge of black holes disrupting stars spin round. This suggests that there is a whole colony of burning stars that have yet to be discovered.

Astronomers were alerted to the star’s presence by an X-ray flare that appeared to come from the center of neighboring galaxy 2MASX J02301709+2836050, about 500 million light-years from the Milky Way . Named Swift J0230, it was discovered in its first appearance by a new instrument developed by scientists at the Neil Gehrels Swift Observatory.

They quickly planned the next Swift observation, discovering that instead of disintegrating as expected, it would glow brightly for seven to 10 days and then suddenly dim, repeating this process about every 25 days. time.

Similar behavior has been observed in so-called quasi-periodic flares and periodic nuclear transits, in which matter is stripped from a star by a black hole as its orbit takes it come closer, but they differ in the frequency at which they erupt and whether they are in X-ray or optical light, the dominant burst. Swift J0230’s steady emission lies somewhere in the middle, suggesting it is the “missing link” between the two types of explosions.

Using proposed models for these two types of events as a guide, scientists concluded that the Swift J0230 explosion represents a star similar in size to our sun in a circular orbit. ellipse around a low-mass black hole at its galactic center. As the star’s orbit approaches the black hole’s intense gravity, matter equivalent to the mass of three Earths is torn from the star’s atmosphere and heats up as it falls into the black hole

The intense heat, about 2 million degrees Celsius, released a huge amount of X-rays that were first captured by the Swift satellite.

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

“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. 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.”

Dr. Rob Eyles-Ferris, who worked with Dr. Evans on the Swift satellite, recently completed his Ph.D. at Leicester, which includes the study of stars disrupted by black holes.“In most systems we have seen before, the star is completely destroyed,” he explains. Swift J0230 is an exciting addition to the partially perturbed class of stars because it shows us that these two classes of already found objects are actually connected to each other, with our new system provide us the missing link.

Dr Kim Page from the University of Leicester, who led the data analysis for the study, said: “Since we found Swift J0230 several months after temporarily activating our new search engine, We hope there are still many more objects like this waiting to be discovered.”

Dr.Chris Nixon is a theoretical astrophysicist who recently moved from the University of Leicester to the University of Leeds. He led the theoretical interpretation of this event.

They estimate that the black hole is around 10,000 to 100,000 times the mass of our sun, which is quite small for the supermassive black holes usually found at the center of galaxies. The black hole at the center of our own galaxy is thought to be 4 million solar masses, while most are in the region of 100 million solar masses.

It is the first discovery to be made using the new transient detector for the Swift satellite, developed by the University of Leicester team and running on their computers. When an extreme event takes place, causing an X-ray burst in a region of the sky where there were previously no X-rays, astronomers call it an astronomical X-ray transient. Despite the extreme events they herald, these events are not easy to find, or at least, not quickly—and so this new tool was developed to look for new types of transients in real time.

Dr. Evans adds, “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. 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.”

Dr. Caroline Harper, Head of Space Science at the UK Space Agency, said, “This is yet another exciting discovery from the world-leading Swift mission—a low mass black hole taking ‘bites’ from a sun-like star whenever it orbits close enough.”

“The UK Space Agency has been working in partnership with NASA on this mission for many years; the UK led on the development of hardware for two of the key science instruments and we provided funding for the Swift Science Data Center, which we continue to support. We look forward to even more insights from Swift about gamma ray bursts throughout the cosmos, and the massive events that cause them, in the future.”

Provided by University of Leicester