Astronomers have observed mysterious X-ray flashes emanating from a nearby supermassive black hole, 1ES 1927+654. The sudden increase in frequency of the flashes, from every 18 minutes to every seven minutes over two years, has left scientists baffled. Researchers believe that a spinning white dwarf, an extremely compact core of a dead star, may be responsible for the phenomenon.
The team, led by Megan Masterson and colleagues, suggests that the white dwarf is orbiting the black hole at an incredibly close distance – just a few million miles from the event horizon. This proximity would normally result in the object being torn apart by gravitational forces, but it’s thought to be held together by a “kick-back” effect caused by shedding of its outer layer into the black hole.
The researchers estimate that the white dwarf is about one-tenth the mass of the sun and is likely to shed part of its outer layer, preventing it from crossing the event horizon. This scenario would produce the observed X-ray patterns, which are indicative of a close-proximity source.
The team plans to continue observing the system using existing and future telescopes, including the space-based gravitational-wave detector LISA, scheduled for launch in the mid-2030s. By studying this phenomenon, scientists hope to gain new insights into the extreme physics at work in black holes’ innermost environments.
“We’ve never seen this dramatic variability in the rate at which it’s flashing,” Masterson said. “This looked absolutely nothing like a normal black hole.”
Source: https://phys.org/news/2025-01-astronomers-ray-nearby-supermassive-black.html