gam Cep b
Astrophysical Synthesis & Habitability Characterization
gam Cep b is a confirmed gas giant exoplanet orbiting the star gam Cep, located approximately 46 light-years (14.1 parsecs) from the Solar System. First announced in 2003 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 2987.587 Earth masses (9.4 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.43 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 19.12 g⊕ (187.5 m/s²), and an escape velocity of 172.9 km/s.
In its orbital architecture around gam Cep, gam Cep b completes one full revolution every 904 Earth days (2.48Julian years) at a semi-major axis of 1.978 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 23.8 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.07 carries the world between 1.8395 AU at periapsis and 2.1165 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 356 K (+83°C / +181°F) and receiving 3.02 S⊕ (~4,115 W/m²), gam Cep b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star gam Cep is classified as an orange K-type star of spectral type K1 III-IV with an effective photospheric temperature of 4,775 K, a radius of 4.74 R☉, a mass of 1.26 M☉, an estimated bolometric luminosity of 10.479 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.7 Gyr and a metallicity of [Fe/H] = 0.2 dex (metal-rich relative to the Sun). From Earth, gam Cep shines at apparent V-band magnitude 3.23 (visible to the unaided human eye under dark skies) in the Northern celestial hemisphere.
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 | gam Cep |
| Spectral Type | K1 III-IV |
| Effective Temp (Teff) | 4,775 K |
| Stellar Radius | 4.7400 R☉ |
| Stellar Mass | 1.2600 M☉ |
| Bolometric Luminosity | 10.479 L☉ |
| Metallicity [Fe/H] | 0.200 dex |
| Stellar Age | 5.700 Gyr |
| Apparent Magnitude | V: 3.230 · G: 2.926 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.978000 AU |
| Orbital Period | 904 days |
| Mean Orbital Velocity | 23.8 km/s |
| Orbital Eccentricity (e) | 0.07000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 8.43 g/cm³ (172.9 km/s vesc) |
| Insolation Flux | 3.0238 S⊕ (~4,115 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 46.000 LY (14.102 pc) |