Astronomers have discovered a unique phenomenon where a white dwarf and a red dwarf orbiting each other emit radio pulses every two hours. Led by Dutch scientist Iris de Ruiter, an international team of researchers analyzed data from several telescopes to determine the origin of these pulses with certainty for the first time.
The discovery was made possible by improved analysis techniques that allowed researchers to detect radio pulses lasting seconds to minutes in stars within the Milky Way. De Ruiter, now a postdoctoral researcher at the University of Sydney, had previously developed a method to search for such pulses and discovered a single pulse in 2015 observations. Further analysis revealed six more pulses from the same source.
Red and white dwarf duo
Follow-up observations with telescopes in Arizona and Texas showed that it was not one flashing star but two stars causing the pulse. The two stars, a red dwarf and a white dwarf, orbit each other every 125 minutes at a distance of about 1,600 light-years from Earth.
Researchers believe that the radio emission is caused by the interaction between the red dwarf and the white dwarf’s magnetic field. Future studies will focus on the ultraviolet emission of ILTJ1101 to determine the temperature of the white dwarf and learn more about white and red dwarfs.
“This discovery was especially cool as it added new pieces to the puzzle,” says de Ruiter. “We worked with experts from various disciplines, using different techniques and observations to get closer to the solution.”
The finding breaks the monopoly held by neutron stars on bright radio pulses, as several other research groups have discovered similar systems without proving their origin. Researchers are now searching all available data to find more long-period pulses.
Source: https://phys.org/news/2025-03-white-dwarf-red-duo-emit.html