There’s a black hole eating a star out there at an astonishing rate.
University of Leicester astronomers discovered a star, similar to our Sun, that a relatively small black hole is devouring. Every close orbit results in the star losing a mass equivalent to three Earths!
Watching a Black Hole Eating a Star
The research, chronicled in Nature Astronomy, could be the “missing link” in understanding how black holes disrupt the stars that orbit them. Funded by the UK Space Agency and the UK Science and Technology Facilities Council, this discovery is instrumental in propelling our grasp of celestial phenomena.
An intense X-ray flash originating from the center of galaxy 2MASX J02301709+2836050 is what initially captured the team’s attention. That galaxy is approximately 500 million light-years from the Milky Way.
The anomaly has been designated as Swift J0230. And it was detected in real-time thanks to a pioneering tool designed for the Neil Gehrels Swift Observatory.
Further investigations revealed a curious pattern: Swift J0230 would radiate intensely for about a week, then go dark, resuming its cycle roughly every 25 days.
How a Black Holes “Eats” Star
This behavior parallels certain phenomena involving stars having materials torn by black holes due to close orbits. However, the Swift J0230’s emission pattern positioned it as a bridge between two known categories of these eruptions.
Drawing from existing models, researchers concluded that Swift J0230 demonstrates a Sun-sized star, trapped in an elliptical orbit around a black hole with low mass, situated at the core of its galaxy.
As this star nears the black hole, a gravitational tug wrests away material equivalent to three Earth masses. This process superheats the material to about 2 million degrees Celsius, triggering the massive X-ray emissions detected by the Swift satellite.
Dr. Phil Evans, the lead author, remarked on the unprecedented nature of this find: a Sun-like star being intermittently torn apart by a relatively small black hole. Labeling the phenomenon as “repeated, partial tidal disruption,” Dr. Evans highlighted that such events had been rare finds until now, falling into one of two categories based on their frequency. This new discovery bridges the gap, providing a more comprehensive understanding.
Dr. Rob Eyles-Ferris, who contributed to the Swift satellite study, emphasized the singularity of Swift J0230. Unlike most observed systems where stars are entirely destroyed, this system offers insights into a middle ground. The finding unifies the two previously identified categories of partially disrupted stars.
Further, Dr. Kim Page, part of the study’s data analysis team, is confident that many more similar objects await discovery.
In terms of mass, the team estimates that the black hole is between 10,000 to 100,000 times that of our Sun. That’s a mere fraction when compared to supermassive black holes typically anchoring galaxies. For perspective, our galaxy’s central black hole weighs in at 4 million solar masses.
The Tool That Helped Detect the Black Hole Eating a Star
The University of Leicester team conceptualized and designed a novel transient detector for the Swift satellite, facilitating this breakthrough. This tool instantly detects astronomical X-ray transients—rare and extreme X-ray bursts in previously silent sky regions.
Dr. Caroline Harper, the Head of Space Science at the UK Space Agency, praised the globally-acclaimed Swift mission, shedding light on a minuscule black hole periodically “snacking” on a Sun-like star. The mission’s continued partnership with NASA promises further invaluable cosmic insights.