Astronomers have discovered a super-Earth exoplanet orbiting the red dwarf star Gliese 625.
Its low activity combined with its long rotation period, of more than 70 days, makes Gliese 625 a very interesting candidate to search for rocky planets.
The newly-discovered planet, Gliese 625b, has a mass of no less than 2.8 times that of Earth, making it a so-called ‘super-Earth.’
Alejandro Suárez Mascareño, an astronomer at Geneva Observatory and the Instituto de Astrofisica de Canarias, and co-authors made the discovery using observations of Gliese 625 collected by the HARPS-N spectrograph at the Italian Telescopio Nazionale Galileo, a 3.6-m telescope located at the Roque de los Muchachos Observatory on La Palma, Canary Islands, Spain.
Gliese 625b does fall within its parent star’s habitable zone.
The planet orbits Gliese 625 once every 14.6 days at a distance of only 0.078 AU.
“Gliese 625b is a small super-Earth at the inner edge of the habitable zone of its star,” Mascareño and his colleagues said.
“We find that the planet might potentially host liquid water depending on its atmospheric condition.”
“Using a basic estimation of the equilibrium temperature, and a correction using the greenhouse calculated to estimate the surface temperature, we estimate a mean surface temperature of 171 degrees Fahrenheit (77 degrees Celsius, or 350 degrees Kelvin) and Earth-like greenhouse effect.”
“The presence of one or more extra planets around Gliese 625 cannot yet be ruled out at longer orbital periods, but finding them will not be easy,” they added.
A. Suárez Mascareño et al. 2017. HADES RV Programme with HARPS-N at TNG: V. A super-Earth on the inner edge of the habitable zone of the nearby M-dwarf GJ 625. Astronomy & Astrophysics, submitted for publication; arXiv: 1705.06537