Gaia-5 b
Astrophysical Synthesis & Habitability Characterization
Gaia-5 b is a confirmed gas giant exoplanet orbiting the star Gaia-5, located approximately 134.3 light-years (41.18 parsecs) from the Solar System. First announced in 2025 by European Space Agency (ESA) Gaia Satellite using the Astrometry detection technique, this world measures 12.1 Earth radii (1.08 Jupiter radii) and has a measured mass of 6633.079 Earth masses (20.87 Jupiter masses). Combining its mass and radius yields a mean bulk density of 20.65 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 45.3 g⊕ (444.24 m/s²), and an escape velocity of 261.9 km/s.
In its orbital architecture around Gaia-5, Gaia-5 b completes one full revolution every 358.62 Earth days. The planet follows a highly eccentric trajectory (e = 0.6423), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.100 R⊕, Gaia-5 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star Gaia-5 is classified as a stellar host with an effective photospheric temperature of 3,447 K, a radius of 0.345 R☉, a mass of 0.339 M☉, an estimated bolometric luminosity of 0.015 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.2 Gyr and a metallicity of [Fe/H] = -0.18 dex (metal-poor relative to the Sun). From Earth, Gaia-5 shines at apparent V-band magnitude 14.61 (faint and requiring research-grade or CCD telescopic photometry) 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: European Space Agency (ESA) Gaia Satellite · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Gaia-5 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,447 K |
| Stellar Radius | 0.3450 R☉ |
| Stellar Mass | 0.3390 M☉ |
| Bolometric Luminosity | 0.015 L☉ |
| Metallicity [Fe/H] | -0.180 dex |
| Stellar Age | 8.200 Gyr |
| Apparent Magnitude | V: 14.610 · G: 13.229 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 358.62 days |
| Orbital Eccentricity (e) | 0.64230 |
| Orbital Inclination (i) | 129.7000° |
| Mean Bulk Density | 20.65 g/cm³ (261.9 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 134.300 LY (41.181 pc) |