Astronomers trace mystery radio signals back to cosmic odd couple of white dwarf and sun-like star
Astronomers have traced a mysterious radio signal back to a cosmic odd couple comprised of a dead star, a white dwarf, and its stellar companion, a sun-like star.
- "As a bonus, we also saw the white dwarf moving behind a region with a strong magnetic field, most likely a 'stellar prominence,' which is a large loop of plasma erupting from a star's surface," team member Natasha Hurley-Walker of the International Centre for Radio Astronomy Research (ICRAR), Curtin University, Australia, said.
- The unusual system consists of a small and highly energetic white dwarf pulsar, orbiting a much larger star similar to our sun.
- The white dwarf in the newly discovered system, designated GPM J071507−114153 and located around 5,000 light-years away, spins once every eight minutes, sending out radio pulses.
"So we know that the pulsations are coming from a region close to the white dwarf, or possibly even from the white dwarf itself." The pulses seen by the team also allowed them to detect stellar flares erupting on the sun-like star.
Several previously discovered LPT systems contain a white dwarf and a companion star, but it has been unclear which of the two stars was generating the radio pulses.
- (Image credit: South African Radio Astronomy Observatory (SARAO)) Hurley-Walker and the team at ICRAR have been at the cutting edge of rare star systems like this.
- These radio pulses have been seen from binary systems with smaller and cooler red dwarf stars before, but rarely from a system like GPM J071507−114153.
- (Image credit: ICRAR) "This is the first time the pulses are clear enough to see the white dwarf moving in its orbit around its companion," team leader and commissioning scientist with the Square Kilometre Array Observatory (SKA), Sam McSweeney, said in a statement.
- "If we are already making such discoveries with precursor telescopes, just imagine how many more star systems we will be able to find, and what a beautifully detailed view of their signals we will have, once the SKA telescopes are completely built," McSweeney said.
- GPM J071507−114153 belongs to a class of celestial objects called long-period transients (LPTs) known to produce radio signals that switch on and off over intervals of minutes or hours.
How this summary was made: extractive summary — built from the sources' own reporting. It is drawn only from the reporting of the sources listed below — read the originals for full detail. How we summarize →