HD 34445 g
Astrophysical Synthesis & Habitability Characterization
HD 34445 g is a confirmed gas giant exoplanet orbiting the star HD 34445, located approximately 150.3 light-years (46.09 parsecs) from the Solar System. First announced in 2017 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.6 Earth radii (1.21 Jupiter radii) and has a measured mass of 120.6 Earth masses (0.38 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.26 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.65 g⊕ (6.37 m/s²), and an escape velocity of 33.3 km/s.
In its orbital architecture around HD 34445, HD 34445 g completes one full revolution every 5700 Earth days (15.61Julian years) at a semi-major axis of 6.36 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 12.1 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.032 (ranging from 6.1565 AU at periapsis to 6.5635 AU at apoapsis), the planet experiences minimal orbital distance variation.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 131 K (-142°C / -224°F) and an incident flux of 0.05 S⊕ (~68 W/m²), surface water and volatile species on HD 34445 g would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 34445 is classified as a solar-type yellow star of spectral type G0 V with an effective photospheric temperature of 5,836 K, a radius of 1.38 R☉, a mass of 1.07 M☉, an estimated bolometric luminosity of 1.982 L☉. Stellar evolution modeling indicates an estimated stellar age of 8.5 Gyr and a metallicity of [Fe/H] = 0.14 dex (metal-rich relative to the Sun). From Earth, HD 34445 shines at apparent V-band magnitude 7.31 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 34445 system is a multi-planet architecture hosting 6 confirmed worlds, with HD 34445 g sharing its stellar neighborhood alongside HD 34445 e, HD 34445 d, HD 34445 c, HD 34445 f, HD 34445 b.
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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 34445 |
| Spectral Type | G0 V |
| Effective Temp (Teff) | 5,836 K |
| Stellar Radius | 1.3800 R☉ |
| Stellar Mass | 1.0700 M☉ |
| Bolometric Luminosity | 1.982 L☉ |
| Metallicity [Fe/H] | 0.140 dex |
| Stellar Age | 8.500 Gyr |
| Apparent Magnitude | V: 7.310 · G: 7.149 |
| System Architecture | 1 Star, 6 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 6.360000 AU |
| Orbital Period | 5700 days |
| Mean Orbital Velocity | 12.1 km/s |
| Orbital Eccentricity (e) | 0.03200 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.26 g/cm³ (33.3 km/s vesc) |
| Insolation Flux | 0.0497 S⊕ (~68 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 150.300 LY (46.091 pc) |