Gliese 667 Cb is an

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first det ...

orbiting the star

Gliese 667 C Gliese 667 (142 G. Scorpii) is a triple-star system in the constellation Scorpius lying at a distance of about from Earth. All three of the stars have masses smaller than the Sun. To the naked eye, the system appears to be a single fai ...

, a member of the Gliese 667 triple-star system. It is the most massive planet discovered in the system and is likely a

super-Earth A super-Earth is a type of exoplanet with a mass higher than Earth, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17.1 times Earth's, respectively. The term "super-Earth" refers only to t ...

or a

mini-Neptune A Mini-Neptune (sometimes known as a gas dwarf or transitional planet) is a planet less massive than Neptune but resembling Neptune in that it has a thick hydrogen-helium atmosphere, probably with deep layers of ice, rock or liquid oceans (made o ...

. Orbital-stability analysis indicates that it cannot be more than twice its minimum mass. It orbits too close to the star to be in the

habitable zone In astronomy and astrobiology, the habitable zone (HZ), or more precisely the circumstellar habitable zone (CHZ), is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressu ...

and thus not suitable for life as we know it.

Eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

analysis indicates that Gliese 667 Cb is not a rocky planet. The planet is likely to be

tidally locked Tidal locking between a pair of co-orbiting astronomical bodies occurs when one of the objects reaches a state where there is no longer any net change in its rotation rate over the course of a complete orbit. In the case where a tidally locked ...

. Thus, one side of the planet is in permanent daylight and the other side in permanent darkness.

References

Gliese 667 Exoplanets discovered in 2009 Exoplanets detected by radial velocity Scorpius 6 {{extrasolar-planet-stub