gam1 Leo b
Astrophysical Synthesis & Habitability Characterization
gam1 Leo b is a confirmed gas giant exoplanet orbiting the star gam1 Leo, located approximately 130.1 light-years (39.89 parsecs) from the Solar System. First announced in 2009 by Bohyunsan Optical Astronomical Observatory 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 2790.43 Earth masses (8.78 Jupiter masses). Combining its mass and radius yields a mean bulk density of 7.88 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 17.86 g⊕ (175.15 m/s²), and an escape velocity of 167.1 km/s.
In its orbital architecture around gam1 Leo, gam1 Leo b completes one full revolution every 428.5 Earth days (1.17Julian years) at a semi-major axis of 1.19 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 30.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.144 carries the world between 1.0186 AU at periapsis and 1.3614 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1081 K (+808°C / +1486°F) and receiving 228.51 S⊕ (~311,003 W/m²), gam1 Leo b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star gam1 Leo is classified as an orange K-type star of spectral type K1 IIIb Fe-0.5 with an effective photospheric temperature of 4,330 K, a radius of 31.88 R☉, a mass of 1.23 M☉, an estimated bolometric luminosity of 320.537 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.412 Gyr and a metallicity of [Fe/H] = -0.51 dex (metal-poor relative to the Sun). From Earth, gam1 Leo shines at apparent V-band magnitude 1.995 (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: Bohyunsan Optical Astronomical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | gam1 Leo |
| Spectral Type | K1 IIIb Fe-0.5 |
| Effective Temp (Teff) | 4,330 K |
| Stellar Radius | 31.8800 R☉ |
| Stellar Mass | 1.2300 M☉ |
| Bolometric Luminosity | 320.537 L☉ |
| Metallicity [Fe/H] | -0.510 dex |
| Stellar Age | 2.412 Gyr |
| Apparent Magnitude | V: 1.995 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.190000 AU |
| Orbital Period | 428.5 days |
| Mean Orbital Velocity | 30.2 km/s |
| Orbital Eccentricity (e) | 0.14400 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 7.88 g/cm³ (167.1 km/s vesc) |
| Insolation Flux | 228.5105 S⊕ (~311,003 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 130.100 LY (39.888 pc) |