HD 13167 b
Astrophysical Synthesis & Habitability Characterization
HD 13167 b is a confirmed gas giant exoplanet orbiting the star HD 13167, located approximately 485.8 light-years (148.93 parsecs) from the Solar System. First announced in 2018 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 13.1 Earth radii (1.17 Jupiter radii) and has a measured mass of 1052.017 Earth masses (3.31 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.58 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.13 g⊕ (60.11 m/s²), and an escape velocity of 100.2 km/s.
In its orbital architecture around HD 13167, HD 13167 b completes one full revolution every 2613 Earth days (7.15Julian years) at a semi-major axis of 4.1 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 17.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.563, swinging from 1.7917 AU at periapsis out to 6.4083 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.100 R⊕, HD 13167 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 13167 is classified as a solar-type yellow star of spectral type G3 V with an effective photospheric temperature of 5,671 K, a radius of 2.39 R☉, a mass of 1.35 M☉, an estimated bolometric luminosity of 5.301 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.19 dex (metal-rich relative to the Sun). From Earth, HD 13167 shines at apparent V-band magnitude 8.34 (accessible to binoculars and small amateur telescopes) in the Southern 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 13167 |
| Spectral Type | G3 V |
| Effective Temp (Teff) | 5,671 K |
| Stellar Radius | 2.3900 R☉ |
| Stellar Mass | 1.3500 M☉ |
| Bolometric Luminosity | 5.301 L☉ |
| Metallicity [Fe/H] | 0.190 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 8.340 · G: 8.160 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 4.100000 AU |
| Orbital Period | 2613 days |
| Mean Orbital Velocity | 17.1 km/s |
| Orbital Eccentricity (e) | 0.56300 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.58 g/cm³ (100.2 km/s vesc) |
| Insolation Flux | 0.5428 S⊕ (~739 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 485.800 LY (148.934 pc) |