GJ 667 C g
Astrophysical Synthesis & Habitability Characterization
GJ 667 C g is a confirmed super-earth exoplanet orbiting the star GJ 667 C, located approximately 23.6 light-years (7.24 parsecs) from the Solar System. First announced in 2013 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 1.99 Earth radii and has a measured mass of 4.6 Earth masses. Combining its mass and radius yields a mean bulk density of 3.22 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.16 g⊕ (11.38 m/s²), and an escape velocity of 17 km/s.
In its orbital architecture around GJ 667 C, GJ 667 C g completes one full revolution every 256.2 Earth days at a semi-major axis of 0.549 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 23.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.08 carries the world between 0.5051 AU at periapsis and 0.5929 AU at apoapsis, driving measurable seasonal insolation cycles.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for GJ 667 C g place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star GJ 667 C is classified as a low-mass red dwarf of spectral type M1.5 V with an effective photospheric temperature of 3,350 K, a mass of 0.33 M☉. Stellar evolution modeling indicates an estimated stellar age of 2 Gyr and a metallicity of [Fe/H] = -0.55 dex (metal-poor relative to the Sun). From Earth, GJ 667 C shines at apparent V-band magnitude 10.602 (faint and requiring research-grade or CCD telescopic photometry) in the Southern celestial hemisphere. The GJ 667 C system is a multi-planet architecture hosting 5 confirmed worlds, with GJ 667 C g sharing its stellar neighborhood alongside GJ 667 C b, GJ 667 C c, GJ 667 C f, GJ 667 C e.
Methodology: Computed using the Schulze-Makuch et al. (2011) weighted metric comparing physical interior (radius, estimated density) and surface thermal regime (escape velocity, equilibrium temperature).
Discovery Facility: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 667 C |
| Spectral Type | M1.5 V |
| Effective Temp (Teff) | 3,350 K |
| Stellar Radius | — |
| Stellar Mass | 0.3300 M☉ |
| Metallicity [Fe/H] | -0.550 dex |
| Stellar Age | 2.000 Gyr |
| Apparent Magnitude | V: 10.602 · G: 9.380 |
| System Architecture | 3 Stars, 5 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.549000 AU |
| Orbital Period | 256.2 days |
| Mean Orbital Velocity | 23.3 km/s |
| Orbital Eccentricity (e) | 0.08000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 3.22 g/cm³ (17 km/s vesc) |
| Insolation Flux | 0.0455 S⊕ (~62 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 23.600 LY (7.244 pc) |