Astronomers discover a sun-like star being “repeatedly shredded” by a black hole
Astronomers have observed that a star like the Sun is “repeatedly torn apart and consumed” by a black hole located about 500 light-years away.
This dramatic event led to the generation of regular bursts of light approximately every 25 days, which scientists at the University of Leicester discovered.
Normally, black hole explosions — known as tidal disruption events, or TDEs — appear when a black hole consumes a star, but frequent emissions mean they only partially destroy stars over and over again.
In cases where explosions are repeated, two types of explosions occur: those that occur every few hours and those that occur every year or so, according to scientists.
In this case, the team said, the regularity of emissions between the two decreased. Observations showed that instead of decaying as expected, the star - called Swift J0230 - shines brightly for seven to 10 days and then suddenly goes out, repeating this process approximately every 25 days.
The scientists said their work, published in the journal Nature Astronomy, provides the “missing link” in understanding how black holes disrupt the stars they orbit.
Dr Rob Isles-Ferris, who recently completed his PhD at the University of Leicester, explained: “In most systems we have seen in the past, the star has been completely destroyed. “Swift J0230 is an exciting addition to the partially inactivated class of stars.”
Lead author Dr Phil Evans, from the University of Leicester's School of Physics and Astronomy, noted: "This is the first time we have seen a star like our Sun." “It is repeatedly being torn apart and consumed by a low-mass black hole.”
Models of Swift J0230's explosion indicate that the star is of a similar size to the Sun, and is in an elliptical orbit around a low-mass black hole at the center of its galaxy.
Calculations indicate that material equivalent to the mass of three terrestrial planets was extracted from Swift J0230's atmosphere and heated as it fell into the black hole.
The intense heat, at around 2 million degrees Celsius, releases a huge amount of X-rays that were captured for the first time by NASA's Neil Gehrels Swift Observatory.
Scientists estimate that the mass of the black hole ranges from 10,000 to 100,000 times the mass of the sun, which is a small size for a massive black hole.
Swift J0230 was observed using a new instrument known as the Transient Detector, which was developed by the University of Leicester team for the Neil Girls Swift Observatory.
Dr Kim Page, from the University of Leicester, who analyzed the data for the study, said: “Given that we found Swift J0230 within a few months of enabling our new transient hunting tool, we expect there will be many more like this, waiting to be discovered. To be exposed.”
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