HD 33142 b
Astrophysical Synthesis & Habitability Characterization
HD 33142 b is a confirmed gas giant exoplanet orbiting the star HD 33142, located approximately 395.9 light-years (121.38 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 13.7 Earth radii (1.22 Jupiter radii) and has a measured mass of 400.464 Earth masses (1.26 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.86 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.13 g⊕ (20.89 m/s²), and an escape velocity of 60.5 km/s.
In its orbital architecture around HD 33142, HD 33142 b completes one full revolution every 330 Earth days at a semi-major axis of 1.074 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 35.4 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.049 (ranging from 1.0214 AU at periapsis to 1.1266 AU at apoapsis), the planet experiences minimal orbital distance variation.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 478 K (+205°C / +401°F) and receiving 8.68 S⊕ (~11,811 W/m²), HD 33142 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 33142 is classified as an orange K-type star of spectral type K0 III with an effective photospheric temperature of 5,025 K, a radius of 4.17 R☉, a mass of 1.52 M☉, an estimated bolometric luminosity of 9.947 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.72 Gyr and a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, HD 33142 shines at apparent V-band magnitude 7.96 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 33142 system is a multi-planet architecture hosting 3 confirmed worlds, with HD 33142 b sharing its stellar neighborhood alongside HD 33142 d, HD 33142 c.
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 33142 |
| Spectral Type | K0 III |
| Effective Temp (Teff) | 5,025 K |
| Stellar Radius | 4.1700 R☉ |
| Stellar Mass | 1.5200 M☉ |
| Bolometric Luminosity | 9.947 L☉ |
| Metallicity [Fe/H] | 0.060 dex |
| Stellar Age | 2.720 Gyr |
| Apparent Magnitude | V: 7.960 · G: 7.713 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.074000 AU |
| Orbital Period | 330 days |
| Mean Orbital Velocity | 35.4 km/s |
| Orbital Eccentricity (e) | 0.04900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.86 g/cm³ (60.5 km/s vesc) |
| Insolation Flux | 8.6781 S⊕ (~11,811 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 395.900 LY (121.375 pc) |