HD 131496 b
Astrophysical Synthesis & Habitability Characterization
HD 131496 b is a confirmed gas giant exoplanet orbiting the star HD 131496, located approximately 430 light-years (131.85 parsecs) from the Solar System. First announced in 2011 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.4 Earth radii (1.2 Jupiter radii) and has a measured mass of 572.094 Earth masses (1.8 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.31 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.19 g⊕ (31.28 m/s²), and an escape velocity of 73.1 km/s.
In its orbital architecture around HD 131496, HD 131496 b completes one full revolution every 896 Earth days (2.45Julian years) at a semi-major axis of 2.01 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 24.4 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.181 carries the world between 1.6462 AU at periapsis and 2.3738 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.400 R⊕, HD 131496 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 HD 131496 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 4,846 K, a radius of 4.44 R☉, a mass of 1.34 M☉, an estimated bolometric luminosity of 9.754 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.7 Gyr and a metallicity of [Fe/H] = 0.25 dex (metal-rich relative to the Sun). From Earth, HD 131496 shines at apparent V-band magnitude 7.8 (accessible to binoculars and small amateur telescopes) 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 131496 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 4,846 K |
| Stellar Radius | 4.4400 R☉ |
| Stellar Mass | 1.3400 M☉ |
| Bolometric Luminosity | 9.754 L☉ |
| Metallicity [Fe/H] | 0.250 dex |
| Stellar Age | 2.700 Gyr |
| Apparent Magnitude | V: 7.800 · G: 7.521 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.010000 AU |
| Orbital Period | 896 days |
| Mean Orbital Velocity | 24.4 km/s |
| Orbital Eccentricity (e) | 0.18100 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 1.31 g/cm³ (73.1 km/s vesc) |
| Insolation Flux | 2.4257 S⊕ (~3,301 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 430.000 LY (131.849 pc) |