HD 70642 b
Astrophysical Synthesis & Habitability Characterization
HD 70642 b is a confirmed gas giant exoplanet orbiting the star HD 70642, located approximately 95.5 light-years (29.28 parsecs) from the Solar System. First announced in 2003 by Anglo-Australian Telescope using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13 Earth radii (1.16 Jupiter radii) and has a measured mass of 1239.531 Earth masses (3.9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 3.11 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 7.33 g⊕ (71.88 m/s²), and an escape velocity of 109.2 km/s.
In its orbital architecture around HD 70642, HD 70642 b completes one full revolution every 2124.54 Earth days (5.82Julian years) at a semi-major axis of 3.318 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 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.175 carries the world between 2.7373 AU at periapsis and 3.8987 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 151 K (-122°C / -188°F) and an incident flux of 0.09 S⊕ (~127 W/m²), surface water and volatile species on HD 70642 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 70642 is classified as a solar-type yellow star of spectral type G6 V with an effective photospheric temperature of 5,732 K, a radius of 0.984 R☉, a mass of 1.078 M☉, an estimated bolometric luminosity of 0.938 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.919 Gyr and a metallicity of [Fe/H] = 0.22 dex (metal-rich relative to the Sun). From Earth, HD 70642 shines at apparent V-band magnitude 7.17 (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: Anglo-Australian Telescope · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 70642 |
| Spectral Type | G6 V |
| Effective Temp (Teff) | 5,732 K |
| Stellar Radius | 0.9840 R☉ |
| Stellar Mass | 1.0780 M☉ |
| Bolometric Luminosity | 0.938 L☉ |
| Metallicity [Fe/H] | 0.220 dex |
| Stellar Age | 0.919 Gyr |
| Apparent Magnitude | V: 7.170 · G: 6.992 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.318000 AU |
| Orbital Period | 2124.54 days |
| Mean Orbital Velocity | 17 km/s |
| Orbital Eccentricity (e) | 0.17500 |
| Orbital Inclination (i) | 29.9000° |
| Mean Bulk Density | 3.11 g/cm³ (109.2 km/s vesc) |
| Insolation Flux | 0.0934 S⊕ (~127 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 95.500 LY (29.276 pc) |