Scientists have detected a new 'super-Earth' planet just 21 light-years away, and they say it could be habitable.
The planet is roughly three times more massive than Earth, and is thought to be a rocky world that may even be cool enough to sustain liquid water, the Daily Mail reported.
It orbits along the inner edge of an M-dwarf star's habitable zone, and researchers are now hoping to characterise its atmosphere and other features to better assess its potential to support life.
The planet was spotted by researchers at the Canary Islands Institute of Astrophysics (IAC) using the 3.6-meter Galileo National Telescope at the Roque de los Muchachos Observatory.
Using the High Accuracy Radial Velocity Planet Searcher for the Northern Hemisphere spectrograph (HARPS-N), they obtained 151 spectra over a period of 3.5 years.
Small variations in its radial velocity revealed the presence of the planet, as a result of its gravitational pull as it circles the red dwarf star GJ625 (Gliese 625).
Each complete orbit takes roughly 14 days, the researchers say.
Scientists estimate the planet to be about 2.8 Earth masses, and sit about .08 astronomical units (AU) from its host star, placing it in the habitable zone.
"As GJ625 is a relatively cool star, the planet is situated at the edge of its habitability zone, in which liquid water can exist on the surface," says Alejandro Suárez Mascareño, one of the study's authors.
"In fact, depending on the cloud cover of its atmosphere and on its rotation, it could potentially be habitable."
The new planet is situated relatively close to our solar system, being just 21 light years away, and the researchers say it's the least massive of the super-Earths found to date.
Moving forward, scientists will attempt to observe the planet as it passes in front of its star, to figure out its density, radius, and characterise its atmosphere, according to Rafael Rebolo, one of the study's authors.
This could be done by "using the high resolution high stability spectrographs on the GTC, or on telescopes of the next generation in the northern hemisphere, such as the Thirty Meter Telescope (TMT)," Rebolo says.
"In the future, new observing campaigns of photometric observations will be essential to try to detect the transit of this planet across its star, given its proximity to the sun," said Jonay González Hernández.
"There is a possibility that there are more rocky planets around GJ625 in orbits which are nearer to, or further away from the star, and within the habitability zone, which we will keep on combing."