Logo

There’s a possible new planet on the universal scene.

The newly uncovered planet, minted M51-ULS-1b, resides in the Whirlpool galaxy, our Milky Way’s neighbor, located 28 million light-years from Earth. It orbits two hosts: a massive star, with a mass at least eight times larger than our sun, and one dead star.

There are no less than 4,800 exoplanets in our home galaxy, the Milky Way. However, planet-hunting technology has yet to reliably extend outward toward further galaxies, which surely boast a variety of their own planets.

“We probably always assumed there would be planets [in other galaxies],” said Harvard-Smithsonian Center astrophysicist Rosanne Di Stefano, whose new report — with help from the University of California, Santa Cruz — was published in Nature Astronomy on Monday. “But to actually find something, it’s a beautiful thing. It’s a humbling experience,” she told Science News.

A relatively novel method helped scientists search for planets outside our galaxy by pointing their telescopes in the direction of binary star systems containing one living and one dead star, called X-ray binaries, named for the X-rays emitted as the collapsing star sucks some of the life from the remaining living star.

If astronomers’ radar shows hiccups in X-ray emission of these particular binary systems, they may deduce that an orbiting planet has caused the brief pause.

Researchers perused data from NASA’s Chandra X-ray telescope for evidence of sporadic X-ray emissions throughout three galaxies: the M101 Pinwheel galaxy, M104 Sombrero galaxy and the M51 Whirlpool galaxy.

Out of a possible 2,624 sources in the data, and ruling out for other potential causes of fluctuations in X-rays, just one suggested a planetary presence.

“We said, ‘Wow. Could this be it?’ ” said Di Stefano.

It’s a hostile environment for Saturn-sized M51-ULS-1b, which fields an onslaught of X-rays and ultraviolet radiation, according to DiStefano.

While some scientists called the research “speculative,” Di Stefano told Science News that the rarity of the observation — out of thousands of potential planetary passes — is a testament to the validity of their findings.

“The real test is finding more planets,” said Di Stefano. And it could be decades before we see M51-ULS-1b transit its host stars again.

“Maybe we were lucky,” she said. “But I think it’s very likely that we were not special. We looked and we found something because there was something to find.”

Comments
anonymous profile image
Powered by RoundtableBuilt on infrastructure designed for real-time media. Learn more at RTB.io.© Roundtable 2026. By using this site you agree to the Terms of Use and Privacy Policy