HD 168863 b
Astrophysical Synthesis & Habitability Characterization
HD 168863 b is a confirmed gas giant exoplanet orbiting the star HD 168863, located approximately 130.1 light-years (39.9 parsecs) from the Solar System. First announced in 2022 by Multiple Observatories using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.7 Earth radii (1.13 Jupiter radii) and has a measured mass of 2154.877 Earth masses (6.78 Jupiter masses). Combining its mass and radius yields a mean bulk density of 5.8 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 13.36 g⊕ (131.02 m/s²), and an escape velocity of 145.7 km/s.
In its orbital architecture around HD 168863, HD 168863 b completes one full revolution every 14773.933 Earth days (40.45Julian years) at a semi-major axis of 10.961 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 8.1 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.187 carries the world between 8.9113 AU at periapsis and 13.0107 AU at apoapsis, driving measurable seasonal insolation cycles.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 63 K (-210°C / -346°F) and an incident flux of 0.00 S⊕ (~4 W/m²), surface water and volatile species on HD 168863 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 168863 is classified as a stellar host with an effective photospheric temperature of 4,905 K, a radius of 0.7778 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.314 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, HD 168863 shines at apparent V-band magnitude 9.35 (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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 168863 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,905 K |
| Stellar Radius | 0.7778 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.314 L☉ |
| Metallicity [Fe/H] | 0.160 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 9.350 · G: 9.068 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 10.961000 AU |
| Orbital Period | 14773.933 days |
| Mean Orbital Velocity | 8.1 km/s |
| Orbital Eccentricity (e) | 0.18700 |
| Orbital Inclination (i) | 129.8390° |
| Mean Bulk Density | 5.8 g/cm³ (145.7 km/s vesc) |
| Insolation Flux | 0.0026 S⊕ (~4 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 130.100 LY (39.898 pc) |