Gliese 667 Cc

Gliese 667 Cc

Exoplanet		List of exoplanets
An artist’s impression of a sunset on Gliese 667 Cc, depicted as an Earth-like planet.
Parent star
Star		Gliese 667C
Constellation		Scorpius
Right ascension	(α)	17h 18m 57.16483s
Declination	(δ)	−34° 59′ 23.1416″
Apparent magnitude	(mV)	10.20
Mass	(m)	0.31 M☉
Radius	(r)	0.42 R☉
Temperature	(T)	3700 K
Metallicity	[Fe/H]	−0.59 ± 0.10
Age		2–10 Gyr
Physical characteristics
Mass	(m)	3.8 M⊕
Radius	(r)	1.54 R⊕
Stellar flux	(F⊙)	0.875 ⊕
Temperature	(T)	277.4 K (4.3 °C; 39.6 °F)
Orbital elements
Semi-major axis	(a)	0.1251 ± 0.03 AU
Eccentricity	(e)	<0.27
Orbital period	(P)	28.155 ± 0.017 d
Inclination	(i)	>30°
Semi-amplitude	(K)	1.5 m/s
Discovery information
Discovery date		2011 (mentioned), 2012 (announced)
Discoverer(s)
Discovery method		Radial velocity (European Southern Observatory)
Discovery status		Published refereed article
Other designations
Gliese 667 Cc, GJ 667 Cc, HR 6426Cc, HD 156384Cc

Gliese 667 Cc (also known as GJ 667Cc, HR 6426Cc, or HD 156384Cc) is an exoplanet 23.62 light years away. It orbits around Gliese 667 C, which is a member of the Gliese 667 triple star system, in the constellation of Scorpius.

Gliese 667 Cc was first announced in a pre-print made public on 21 November 2011 by the European Southern Observatory's High Accuracy Radial Velocity Planet Searcher (HARPS) group using the radial velocity method (Doppler method). The announcement of a refereed journal report came on 2 February 2012 by researchers at the University of Göttingen and the Carnegie Institution for Science and backing up the ESO HARPS group discovery.

The orbit of Gliese 667Cc has a semi-major axis of 0.1251 astronomical units, making its year 28.155 Earth-days long.

Based on GJ 667 C's bolometric luminosity, GJ 667 Cc would receive 90% of the light Earth does; however, much of that electromagnetic radiation would be in the invisible infrared light part of the spectrum. In fact, taking into account solely the star's visual luminosity, the planet actually only receives 20% of the visible light Earth does.

Gliese 667 Cc is heavier than Earth with a minimum mass of about 3.8 Earth masses. Based on black body temperature calculation, GJ 667 Cc should absorb similar but slightly more overall electromagnetic radiation than Earth, making it a little bit warmer (277.4 K (4.3 °C; 39.6 °F)) and consequently placing it slightly closer to the "hot" inner edge of the habitable zone than Earth (254.3 K (−18.8 °C; −1.9 °F)). According to PHL, Gliese 667 Cc is the most Earth-like exoplanet located in the conservative habitable zone of its parent star.

Comparison to Earth

The star Gliese 667 C could host at least 7 planets and 3 of those, all rocky planets (including Gliese 667 Cc), are potentially within the habitable zone.

In fiction

Gliese 667 Cc features in the story The Audience by Sean McMullen in the June 2015 issue of Analog Science Fiction and Fact. In the Alien vs Predator franchise, Gliese 667 Cc was the first planet to be terraformed, being done so by the Weyland Corporation in 2039.

See also

• KELT-4Ab, another exoplanet in a triple star system
• List of potentially habitable exoplanets

References

Preceded by Gliese 581 g

Highest ESI for an Exoplanet 2011 — 2015

Succeeded by Kepler-438b