Astronomers have long been puzzled by strange behavior from a supermassive black hole 270 million light-years away. In recent years, the black hole has exhibited rapid X-ray flashes and plasma jets moving at nearly one-third the speed of light. Researchers believe they have identified a likely culprit for these unusual features: a low-mass white dwarf spinning precariously on the edge of the black hole.
The white dwarf, about as large as Earth, is thought to be shedding matter as it approaches the event horizon, generating ripples in space-time that could produce the observed X-ray flashes. This theory is supported by recent observations and radio data from February, April, and May 2024, which reveal jets of ionized gas extending from either side of the black hole.
The discovery was made by a team of astronomers led by graduate physics student Megan Masterson at the Massachusetts Institute of Technology. According to Masterson, “This would be the closest thing we know of around any black hole,” suggesting that white dwarfs may be able to live near event horizons for extended periods.
Astronomers have been monitoring the black hole since 2018, when it underwent a major X-ray outburst. Since then, they have observed rapid X-ray flashes and changes in the black hole’s properties. The team believes that the white dwarf is responsible for these fluctuations, which could provide valuable insights into the behavior of compact objects near supermassive black holes.
The research was presented at the 245th meeting of the American Astronomical Society.
Source: https://eu.usatoday.com/story/news/nation/2025/01/14/black-hole-white-dwarf-flashes-astronomers/77691237007