A cosmic lighthouse that flashes every 7.9 minutes: astronomers find a white dwarf beaming radio pulses while orbiting a Sun-like star

Since 2021, astronomers have been finding a strange kind of radio signal in the Milky Way. Like a lighthouse, each source flashes on a regular schedule, but instead of the seconds or milliseconds typical of pulsars, the gaps last minutes to hours. These objects are called long-period transients, or LPTs. Only about a dozen are known, and scientists are still working out what powers them.

According to a report from Sci.News published at 3:02 PM EST on Nov. 12, 2026 (04:02 Beijing time on Nov. 13), and a report from Chinese tech site IT之家 (IT Home) published at 09:11 Beijing time on Nov. 13 (8:11 PM EST on Nov. 12), researchers at the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) have published a paper in Nature Astronomy describing a new LPT, GPM J071507−114153. The journal page lists the paper as published online on Nov. 12, 2026. IT Home reports that the system is more than 5,000 light-years from Earth. It has two stars: a low-mass white dwarf, the dense core left behind after a star dies, and a G-type star similar to our Sun. The white dwarf's radio beam sweeps past Earth about every 7.9 minutes. According to the paper's abstract, the pulses are also modulated over a longer period of about 1.3 days, which the team interprets as the time the two stars take to orbit each other.

What's new: in the LPTs previously confirmed as binary systems, the companion has been a smaller, cooler red dwarf. Curtin University says this is the first time radio pulses have been detected from a white dwarf orbiting a Sun-like star. Lead author Sam McSweeney said in Curtin's release that the pulses are clear enough, for the first time, to see the white dwarf moving in its orbit, so the team knows the signal comes from close to the white dwarf, or possibly from the white dwarf itself. The team processed more than 100 hours of radio data at the Pawsey Supercomputing Research Centre. The discovery was a relay across three continents: the Murchison Widefield Array in Australia spotted the signal in a survey of the Milky Way, South Africa's MeerKAT radio telescope pinned down its position, and the W. M. Keck Observatory in Hawaii confirmed through optical observations that the companion is a G-type star.

The pulses also worked as a probe. According to the abstract, the signal's polarization changed rapidly when the white dwarf passed near the far side of its companion, which fits Faraday rotation as the radio waves travel through the companion star's corona. Co-author Natasha Hurley-Walker said the pulses let the team detect stellar flares on the Sun-like star, similar to the solar activity that drives auroras on Earth. The researchers conclude that in LPTs powered by white dwarf binaries, the radio pulses depend heavily on the interaction between the white dwarf and its companion.

What it means for everyday people: this will not change daily life, but it helps answer a basic question about what dead stars do to the stars around them. Repeating signals like these sometimes get linked to aliens in popular discussion, and this study gives a fully natural explanation framework. As bigger radio telescopes such as the Square Kilometre Array come online, astronomers expect to find many more of these objects, which would also give them a new way to study "space weather" on other stars.

Original sources published: Sci.News, Nov 13, 2026, 04:02 Beijing time / Nov 12, 2026, 3:02 PM EST; IT之家 (IT Home), Nov 13, 2026, 09:11 Beijing time / Nov 12, 2026, 8:11 PM EST