L 98-59, likewise called TOI-175, TIC 307210830, is an M dwarf about one-third the mass of the Sun.

The system lies around 34.5 light-years away in the southern constellation of Volans.

It includes 3 transiting exoplanets, recognized by TESS in 2019, in compact orbits of 2.25, 3.7, and 7.45 days, with an external 12.8-day non-transiting world validated in 2021 utilizing ESO’s ESPRESSO spectrograph.

These worlds show a varied variety of sizes (0.8-1.6 Earth radii), masses (0.5-3 Earth mases), and most likely structures (Earth-like to potentially water-rich).

In a brand-new research study, Université de Montréal and Trottier Institute for Research on Exoplanets astronomer Charles Cadieux and his associate thoroughly reanalyzed TESS, ESPRESSO, HARPS and Webb information.

They had the ability to identify the worlds’ sizes and masses with extraordinary accuracy.

“We improve the radii of L 98-59b, c, and d to 0.84 Earth radii, 1.33, 1.63, respectively,” they stated.

“We likewise report upgraded masses of 0.46 Earth masses for L 98-59b, 2 for L 98-59c, and 1.64 for L 98-59d, and a minimum mass of 2.82 for L 98-59e.”

The astronomers likewise validated the presence of a 5th world, L 98-59f, in the star’s habitable zone, where conditions might enable liquid water to exist.

“Finding a temperate world in such a compact system makes this discovery especially amazing,” Dr. Cadieux stated.

“It highlights the amazing variety of exoplanetary systems and enhances the case for studying possibly habitable worlds around low-mass stars.”

“These brand-new outcomes paint the most total image we’ve ever had of the remarkable L 98-59 system,” he included.

“It’s an effective presentation of what we can accomplish by integrating information from area telescopes and high-precision instruments in the world, and it offers us crucial targets for future climatic research studies with the NASA/ESA/CSA James Webb Space Telescope.”

The refined measurements expose almost completely circular orbits for the inner worlds, a beneficial setup for future climatic detections.

“With its variety of rocky worlds and series of planetary structures, L 98-59 uses a distinct lab to deal with a few of the field’s most pushing concerns: What are super-Earths and sub-Neptunes made from? Do worlds form in a different way around little stars? Can rocky worlds around red overshadows maintain environments gradually?” stated Université de Montréal’s Professor René Doyon, director of Trottier Institute for Research on Exoplanets.

The group’s paper will be released in the Huge Journal

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Charles Cadieux et al2025. Comprehensive Architecture of the L 98-59 System and Confirmation of a Fifth Planet in the Habitable Zone. AJin press; arXiv: 2507.09343