Researchers discovered super-Earth in habitable zone
US researchers have discovered an exoplanet in our cosmic neighborhood that could have liquid water.
The Gliese 251 system with exoplanets GJ 251b and the newly discovered GJ 251c in the foreground
(Image: University of California Irvine)
Could there be life on GJ 251c? The recently discovered exoplanet orbits its star in the so-called habitable zone. By cosmic standards, it is our neighbor.
GJ 251c is presumably a rocky planet like Earth, but significantly larger: it has about four times the mass of Earth. Its central star is Gliese 251, a red dwarf star in the constellation Gemini, which is about 18.2 light-years away from Earth.
GJ 251c takes 54 days to orbit the star. This puts it “in the habitable or 'Goldilocks zone', meaning at the right distance from its star for liquid water to exist on its surface, if it has the right atmosphere,” said Suvrath Mahadevan, an astronomer at Pennsylvania State University (Penn State) in State College. However, it is unclear whether the planet has an atmosphere at all, write the Penn State researchers in the journal The Astronomical Journal.
Discovered with the Habitable Zone Planet Finder
The Penn State team discovered the exoplanet using the Habitable-Zone Planet Finder (HPF), a high-resolution spectrometer at the McDonald Observatory in Texas that operates in the near-infrared spectrum. The instrument can detect the subtle changes in a star's light spectrum caused by the gravity of an exoplanet.
“We call it the Habitable-Zone Planet Finder because we use it to search for worlds that are far enough from their star that liquid water can exist on their surface. That was the central goal of this study,” said Mahadevan. “We are looking for this type of planet because they are our best chance of finding life out there.” GJ 251c is one of the best candidates for the search for biosignatures.
The Penn State team therefore plans to continue observing it in the future when more powerful telescopes become available. “While we cannot yet confirm that GJ 251c has an atmosphere or life, the planet is a promising target for future exploration,” said Mahadevan. “We have made an exciting discovery, but there is still much more to learn about this planet.”
Videos by heise
Besides GJ 251c, another planet orbits Gliese 251, which was already discovered in 2020. Gliese 251b is also a super-Earth, but significantly smaller: it is just under twice the size of Earth. However, it is far too close to the star – it only takes 14.2 days to orbit – for life-friendly conditions to prevail there.
(wpl)
