HD 203030 b
Astrophysical Synthesis & Habitability Characterization
HD 203030 b is a confirmed gas giant exoplanet orbiting the star HD 203030, located approximately 128 light-years (39.25 parsecs) from the Solar System. First announced in 2006 by Palomar Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 14.46 Earth radii (1.29 Jupiter radii) and has a measured mass of 3496.112 Earth masses (11 Jupiter masses). Combining its mass and radius yields a mean bulk density of 6.38 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 16.72 g⊕ (163.97 m/s²), and an escape velocity of 173.9 km/s.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1040 K (+767°C / +1413°F), HD 203030 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 203030 is classified as a solar-type yellow star of spectral type G8 V with an effective photospheric temperature of 5,603 K, a radius of 0.8565 R☉, a mass of 0.94 M☉, an estimated bolometric luminosity of 0.649 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.1 Gyr and a metallicity of [Fe/H] = 0.3 dex (metal-rich relative to the Sun). From Earth, HD 203030 shines at apparent V-band magnitude 8.45 (accessible to binoculars and small amateur telescopes) in the Northern 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: Palomar Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 203030 |
| Spectral Type | G8 V |
| Effective Temp (Teff) | 5,603 K |
| Stellar Radius | 0.8565 R☉ |
| Stellar Mass | 0.9400 M☉ |
| Bolometric Luminosity | 0.649 L☉ |
| Metallicity [Fe/H] | 0.300 dex |
| Stellar Age | 0.100 Gyr |
| Apparent Magnitude | V: 8.450 · G: 8.247 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 487.100000 AU |
| Orbital Period | — |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 6.38 g/cm³ (173.9 km/s vesc) |
| Insolation Flux | 0.0000 S⊕ |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 128.000 LY (39.250 pc) |