G 192-15 c
Astrophysical Synthesis & Habitability Characterization
G 192-15 c is a confirmed sub-neptune exoplanet orbiting the star G 192-15, located approximately 31.1 light-years (9.53 parsecs) from the Solar System. First announced in 2025 by Calar Alto Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 3.87 Earth radii (0.35 Jupiter radii) and has a measured mass of 14.3 Earth masses. Combining its mass and radius yields a mean bulk density of 1.36 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.95 g⊕ (9.32 m/s²), and an escape velocity of 21.5 km/s.
In its orbital architecture around G 192-15, G 192-15 c completes one full revolution every 1219 Earth days (3.34Julian years) at a semi-major axis of 1.137 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 10.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.676, swinging from 0.3684 AU at periapsis out to 1.9056 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 56 K (-217°C / -359°F) and an incident flux of 0.00 S⊕ (~2 W/m²), surface water and volatile species on G 192-15 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star G 192-15 is classified as a low-mass red dwarf of spectral type M5.0 V with an effective photospheric temperature of 2,999 K, a radius of 0.1707 R☉, a mass of 0.132 M☉, an estimated bolometric luminosity of 0.00211 L☉. From Earth, G 192-15 shines at apparent V-band magnitude 14.64 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The G 192-15 system is a multi-planet architecture hosting 2 confirmed worlds, with G 192-15 c sharing its stellar neighborhood alongside G 192-15 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: Calar Alto Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | G 192-15 |
| Spectral Type | M5.0 V |
| Effective Temp (Teff) | 2,999 K |
| Stellar Radius | 0.1707 R☉ |
| Stellar Mass | 0.1320 M☉ |
| Bolometric Luminosity | 0.00211 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 14.640 · G: 12.697 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.137000 AU |
| Orbital Period | 1219 days |
| Mean Orbital Velocity | 10.1 km/s |
| Orbital Eccentricity (e) | 0.67600 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.36 g/cm³ (21.5 km/s vesc) |
| Insolation Flux | 0.0016 S⊕ (~2 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 31.100 LY (9.531 pc) |