GJ 414 A c
Astrophysical Synthesis & Habitability Characterization
GJ 414 A c is a confirmed gas giant exoplanet orbiting the star GJ 414 A, located approximately 38.8 light-years (11.89 parsecs) from the Solar System. First announced in 2021 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 8.4 Earth radii (0.75 Jupiter radii) and has a measured mass of 53.83 Earth masses (0.17 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.5 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.76 g⊕ (7.45 m/s²), and an escape velocity of 28.3 km/s.
In its orbital architecture around GJ 414 A, GJ 414 A c completes one full revolution every 749.83 Earth days (2.05Julian years) at a semi-major axis of 1.4 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 20.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.105 carries the world between 1.253 AU at periapsis and 1.547 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 125 K (-148°C / -234°F) and an incident flux of 0.06 S⊕ (~83 W/m²), surface water and volatile species on GJ 414 A c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star GJ 414 A is classified as an orange K-type star of spectral type K7 V with an effective photospheric temperature of 4,120 K, a radius of 0.68 R☉, a mass of 0.65 M☉, an estimated bolometric luminosity of 0.12 L☉. Stellar evolution modeling indicates an estimated stellar age of 12.4 Gyr and a metallicity of [Fe/H] = 0.24 dex (metal-rich relative to the Sun). From Earth, GJ 414 A shines at apparent V-band magnitude 8.31 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The GJ 414 A system is a multi-planet architecture hosting 2 confirmed worlds, with GJ 414 A c sharing its stellar neighborhood alongside GJ 414 A b.
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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | GJ 414 A |
| Spectral Type | K7 V |
| Effective Temp (Teff) | 4,120 K |
| Stellar Radius | 0.6800 R☉ |
| Stellar Mass | 0.6500 M☉ |
| Bolometric Luminosity | 0.12 L☉ |
| Metallicity [Fe/H] | 0.240 dex |
| Stellar Age | 12.400 Gyr |
| Apparent Magnitude | V: 8.310 · G: 7.728 |
| System Architecture | 2 Stars, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.400000 AU |
| Orbital Period | 749.83 days |
| Mean Orbital Velocity | 20.3 km/s |
| Orbital Eccentricity (e) | 0.10500 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.5 g/cm³ (28.3 km/s vesc) |
| Insolation Flux | 0.0607 S⊕ (~83 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 38.800 LY (11.889 pc) |