A new superterran exoplanet (aka Super-Earth) was found in the stellar habitable zone of the red dwarf star Gliese 163 by the European HARPS team. The planet, Gliese 163c, has a minimum mass of 6.9 Earth masses and takes nearly 26 days to orbit its star. Superterrans are those exoplanets between two and ten Earth masses, which are more likely composed of rock and water. Gliese 163 is a nearby red dwarf star 50 light years away in the Dorado constellation. Another larger planet, Gliese 163b, was also found to orbit the star much closer with a nine days period. An additional third, but unconfirmed planet, might be orbiting the star much farther away.
It receives on average 40% more light from its star than Earth from the Sun, therefore it will be hotter than the Earth.
We don’t know the atmosphere of Gliese 163c is made of yet but, since it may be a scaled up version of Earth the surface temperature of Gliese 163c might be around 60°C. Most complex life can’t survive those temperatures , but microbial life forms can thrive in such a place.
Xavier Bonfils, France’s Joseph Fourier University-Grenoble said “There are a wide range of structures and compositions that allow Gliese 163c to be a habitable planet”.
The NASA Kepler Mission has detected about 27 potential habitable exoplanets candidates out of their over 2,300 exoplanets that are waiting to be confirmed. Some of these bodies seem very Earth-like. Unfortunately, they are much farther away from us than Gliese 163 and it will be nearly impossible to determine if they are really habitable worlds by future observations. However, the statistical analysis of Kepler data suggests that these planets are very common in the galaxy. Therefore, many more Earth-like worlds are waiting to be discovered in our solar neighborhood too, such as Gliese 163c.
The new exoplanets around Gliese 163 were discovered by the European HARPS team led by Xavier Bonfils from the UJF-Grenoble/CNRS-INSU, Institut de Plane ́tologie et d’Astrophysique of Grenoble, France. Other participating scientists are from France, Germany, Portugal, Switzerland, and Belgium. Gliese 163c was announced by team member Thierry Forveille from the Observatoire de Grenoble during the International Astronomical Union session Formation, Detection, and Characterization of Extrasolar Habitable Planets from August 27th to 31st, 2012 in Beijing, China. A paper was submitted to the scientific journal Astronomy & Astrophysics.