HD 30177 b
Astrophysical Synthesis & Habitability Characterization
HD 30177 b is a confirmed gas giant exoplanet orbiting the star HD 30177, located approximately 181.3 light-years (55.59 parsecs) from the Solar System. First announced in 2002 by Anglo-Australian Telescope using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.6 Earth radii (1.12 Jupiter radii) and has a measured mass of 2622.084 Earth masses (8.25 Jupiter masses). Combining its mass and radius yields a mean bulk density of 7.23 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 16.52 g⊕ (162.01 m/s²), and an escape velocity of 161.4 km/s.
In its orbital architecture around HD 30177, HD 30177 b completes one full revolution every 2539 Earth days (6.95Julian years) at a semi-major axis of 3.49 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 15 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.186 carries the world between 2.8409 AU at periapsis and 4.1391 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 148 K (-125°C / -193°F) and an incident flux of 0.10 S⊕ (~135 W/m²), surface water and volatile species on HD 30177 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 30177 is classified as a solar-type yellow star of spectral type G8 V with an effective photospheric temperature of 5,680 K, a radius of 1.019 R☉, a mass of 0.98 M☉, an estimated bolometric luminosity of 0.97 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.55 Gyr and a metallicity of [Fe/H] = 0.43 dex (metal-rich relative to the Sun). From Earth, HD 30177 shines at apparent V-band magnitude 8.41 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 30177 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 30177 b sharing its stellar neighborhood alongside HD 30177 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: Anglo-Australian Telescope · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 30177 |
| Spectral Type | G8 V |
| Effective Temp (Teff) | 5,680 K |
| Stellar Radius | 1.0190 R☉ |
| Stellar Mass | 0.9800 M☉ |
| Bolometric Luminosity | 0.97 L☉ |
| Metallicity [Fe/H] | 0.430 dex |
| Stellar Age | 3.550 Gyr |
| Apparent Magnitude | V: 8.410 · G: 8.215 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.490000 AU |
| Orbital Period | 2539 days |
| Mean Orbital Velocity | 15 km/s |
| Orbital Eccentricity (e) | 0.18600 |
| Orbital Inclination (i) | 65.5000° |
| Mean Bulk Density | 7.23 g/cm³ (161.4 km/s vesc) |
| Insolation Flux | 0.0995 S⊕ (~135 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 181.300 LY (55.587 pc) |