Star Wars-like system discovered with 3 Earth-sized planets orbiting twin suns

An artist’s illustration showing the unusual planetary system TOI-2267. (Image: Mario Sucerquia (University of Grenoble Alpes))

Astronomers have found three Earth-sized planets orbiting twin stars about 120 light-years away – a surprise discovery that challenges long-held theories about where planets form. The system has been dubbed TOI-2267 and was detected using data from NASA's Transiting Exoplanet Survey Satellite, TESS.

Could planets really form in twin star systems?
Binary systems have long been thought too unstable for planetary formation, as the gravitational pull between stars makes it difficult for planets to form and survive. But scientists say TOI-2267 defies that idea. “Our analysis shows a unique planetary arrangement: two planets are transiting one star, and the third is transiting its companion star,” said Sebastián Zúñiga-Fernández from the University of Liège (ULiège). This makes TOI-2267 the first known binary system to host transiting planets around both stars.

What makes this discovery stand out?

According to Francisco J. Pozuelos from the Instituto de Astrofísica de Andalucía (IAA-CSIC), the system is "the most compact and coldest pair of stars with planets known." The discovery was initiated when Pozuelos and his colleagues used their detection tool SHERLOCK to carry out studies on data from TESS and detected hints pointing toward the existence of planets in the system. Further observations were made using a network of observatories, including the SPECULOOS and TRAPPIST telescopes located in Chile, Spain, and Belgium.

Why is TOI-2267 so important in science?

The twin stars in TOI-2267 dance around each other quite closely, in what scientists describe as a "compact binary".
One of its planets resembles the desert world Tatooine from Star Wars, famous for its double sunsets. Despite theories suggesting such conditions would make planet formation impossible, TOI-2267’s planets exist and appear stable.

Pozuelos said the system serves as a “natural laboratory” to study how rocky planets form and survive in extreme environments. Researchers believe future observations with the James Webb Space Telescope could help measure the planets’ masses, densities, and possibly their atmospheres.

What’s next for astronomers?
The team’s findings, published on 24 October in the journal Astronomy & Astrophysics, open new questions about the limits of planet formation. “Finding three Earth-sized worlds within such a close binary system presents a rare opportunity,” Zúñiga-Fernández said. “It allows us to test planet formation theories in complex environments and understand the diversity of worlds in our galaxy.”

The discovery not only challenges assumptions about binary systems but also expands the possibilities for where Earth-like worlds might exist beyond our Solar System.