Astronomers have discovered strange and accelerating X-ray pulses emanating from a black hole, which may indicate the presence of an orbiting white dwarf. The team at MIT observed these flashes in 2022 and 2024, with the pulse frequency increasing from every 18 minutes to every 7.1 minutes over two years.
Lead researcher Megan Masterson explains that while finding oscillations in supermassive black holes is exciting, the changing pulse period on human-observable timescales is unprecedented. The researchers believe a white dwarf’s proximity and shedding of matter could be causing the pulses.
If confirmed, this would be the closest known object to any black hole, with the white dwarf possibly orbiting within millions of miles of the event horizon. To detect gravitational waves from the black hole, which are necessary to confirm the hypothesis, scientists will have to wait for the 2035 launch of LISA (Laser Interferometer Space Antenna).
The discovery has generated interest in the scientific community, with Matt Nicholl stating that finding a white dwarf being consumed by a black hole with LISA would be highly desirable. For now, astronomers are keeping their telescopes pointed at the black hole, awaiting further observations and potential new insights.
Source: https://www.smithsonianmag.com/smart-news/astronomers-found-strange-accelerating-x-ray-pulses-coming-from-a-black-hole-they-might-be-a-sign-of-an-orbiting-white-dwarf-180985832