HD 12235 c
Astrophysical Synthesis & Habitability Characterization
HD 12235 c is a confirmed gas giant exoplanet orbiting the star HD 12235, located approximately 103.6 light-years (31.76 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.5 Earth radii (1.12 Jupiter radii) and has a measured mass of 3135.695 Earth masses (9.87 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.85 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 20.07 g⊕ (196.82 m/s²), and an escape velocity of 177.2 km/s.
In its orbital architecture around HD 12235, HD 12235 c completes one full revolution every 36336.707 Earth days (99.48Julian years) at a semi-major axis of 22.21 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 6.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.174 carries the world between 18.3455 AU at periapsis and 26.0745 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 82 K (-191°C / -312°F) and an incident flux of 0.01 S⊕ (~10 W/m²), surface water and volatile species on HD 12235 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 12235 is classified as a stellar host with an effective photospheric temperature of 5,986 K, a radius of 1.8019 R☉, a mass of 1.1 M☉, an estimated bolometric luminosity of 3.74 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.31 dex (metal-rich relative to the Sun). From Earth, HD 12235 shines at apparent V-band magnitude 5.881 (visible to the unaided human eye under dark skies) in the Northern celestial hemisphere. The HD 12235 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 12235 c sharing its stellar neighborhood alongside HD 12235 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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 12235 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,986 K |
| Stellar Radius | 1.8019 R☉ |
| Stellar Mass | 1.1000 M☉ |
| Bolometric Luminosity | 3.74 L☉ |
| Metallicity [Fe/H] | 0.310 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 5.881 · G: 5.741 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 22.210000 AU |
| Orbital Period | 36336.707 days |
| Mean Orbital Velocity | 6.6 km/s |
| Orbital Eccentricity (e) | 0.17400 |
| Orbital Inclination (i) | 47.7380° |
| Mean Bulk Density | 8.85 g/cm³ (177.2 km/s vesc) |
| Insolation Flux | 0.0076 S⊕ (~10 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 103.600 LY (31.763 pc) |