HD 10647 b
Astrophysical Synthesis & Habitability Characterization
HD 10647 b is a confirmed gas giant exoplanet orbiting the star HD 10647, located approximately 56.5 light-years (17.34 parsecs) from the Solar System. First announced in 2006 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 13.8 Earth radii (1.23 Jupiter radii) and has a measured mass of 298.75 Earth masses (0.94 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.63 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.57 g⊕ (15.4 m/s²), and an escape velocity of 52 km/s.
In its orbital architecture around HD 10647, HD 10647 b completes one full revolution every 989.2 Earth days (2.71Julian years) at a semi-major axis of 2.015 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 22.2 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.15 carries the world between 1.7128 AU at periapsis and 2.3173 AU at apoapsis, driving measurable seasonal insolation cycles.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.800 R⊕, HD 10647 b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star HD 10647 is classified as a warm F-type star of spectral type F9 V with an effective photospheric temperature of 6,218 K, a radius of 1.1 R☉, a mass of 1.11 M☉, an estimated bolometric luminosity of 1.623 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.4 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, HD 10647 shines at apparent V-band magnitude 5.52 (visible to the unaided human eye under dark skies) 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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 10647 |
| Spectral Type | F9 V |
| Effective Temp (Teff) | 6,218 K |
| Stellar Radius | 1.1000 R☉ |
| Stellar Mass | 1.1100 M☉ |
| Bolometric Luminosity | 1.623 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 1.400 Gyr |
| Apparent Magnitude | V: 5.520 · G: 5.382 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.015000 AU |
| Orbital Period | 989.2 days |
| Mean Orbital Velocity | 22.2 km/s |
| Orbital Eccentricity (e) | 0.15000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.63 g/cm³ (52 km/s vesc) |
| Insolation Flux | 0.3471 S⊕ (~472 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 56.500 LY (17.336 pc) |