Astronomers find white dwarf pair orbiting every six minutes, losing energy to gravitational waves

By the Everything Space news desk · 06 Sep 2026 · written from the sources below

Image: Universe Today

The tight binary's fast-decaying orbit makes it a strong candidate for detection by future gravitational wave observatories such as LISA.

Astronomers have identified a binary system of two white dwarf stars, called eRASSU J0608, that orbit each other in just over six minutes. The system was first flagged as an x-ray source pulsing every 374 seconds, prompting researchers to investigate what periodic process could cause such regular bursts.

Data from the NICER and Einstein Probe x-ray observatories revealed that the pulses come from a pair of white dwarfs orbiting so closely that matter shed from one star falls directly onto its companion rather than forming a swirling accretion disk. The x-rays appear as bursts because the superheated material only becomes visible when the stars' alignment allows it.

By comparing the new observations with older data from XMM-Newton spanning more than three years, the researchers found that the stars' orbit is shrinking unusually fast. The pace of this decay matches what would be expected if the system is losing energy through gravitational waves, and the rate ranks among the fastest seen in such systems, suggesting it emits an especially strong gravitational wave signal.

Despite this, the x-ray data alone cannot reveal how far away the system is, and distance matters because gravitational wave strength weakens with distance in the same way light does. The research team hopes to find evidence of a third companion star in the system that could help pin down its distance more precisely.

If the system turns out to be relatively close, its gravitational waves could be detectable by upcoming space-based observatories such as LISA, which are being built to sense signals too faint for current ground-based detectors. Such a discovery could let scientists use the binary as a reference point for calibrating gravitational wave signals from other cosmic sources.

Written in Everything Space’s own words by our news-desk model from the sources above, and checked against them in code: every number in this report appears in its sources, and no sentence is copied from them.