gam Psc b
Astrophysical Synthesis & Habitability Characterization
gam Psc b is a confirmed gas giant exoplanet orbiting the star gam Psc, located approximately 134.7 light-years (41.31 parsecs) from the Solar System. First announced in 2021 by Okayama Astrophysical Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.6 Earth radii (1.21 Jupiter radii) and has a measured mass of 425.89 Earth masses (1.34 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.93 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.3 g⊕ (22.56 m/s²), and an escape velocity of 62.6 km/s.
In its orbital architecture around gam Psc, gam Psc b completes one full revolution every 555.1 Earth days (1.52Julian years) at a semi-major axis of 1.32 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 25.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.204 carries the world between 1.0507 AU at periapsis and 1.5893 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 666 K (+393°C / +739°F) and receiving 33.52 S⊕ (~45,624 W/m²), gam Psc b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star gam Psc is classified as a solar-type yellow star of spectral type G7 III with an effective photospheric temperature of 4,742 K, a radius of 11.2 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 56.908 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.62 dex (metal-poor relative to the Sun). From Earth, gam Psc shines at apparent V-band magnitude 3.693 (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: Okayama Astrophysical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | gam Psc |
| Spectral Type | G7 III |
| Effective Temp (Teff) | 4,742 K |
| Stellar Radius | 11.2000 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 56.908 L☉ |
| Metallicity [Fe/H] | -0.620 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 3.693 · G: 3.414 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.320000 AU |
| Orbital Period | 555.1 days |
| Mean Orbital Velocity | 25.9 km/s |
| Orbital Eccentricity (e) | 0.20400 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.93 g/cm³ (62.6 km/s vesc) |
| Insolation Flux | 33.5227 S⊕ (~45,624 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 134.700 LY (41.311 pc) |