HD 360 b
Astrophysical Synthesis & Habitability Characterization
HD 360 b is a confirmed gas giant exoplanet orbiting the star HD 360, located approximately 363.8 light-years (111.54 parsecs) from the Solar System. First announced in 2021 by Okayama Astrophysical Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 14 Earth radii (1.25 Jupiter radii) and has a measured mass of 238.371 Earth masses (0.75 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.48 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 46.2 km/s.
In its orbital architecture around HD 360, HD 360 b completes one full revolution every 273.1 Earth days at a semi-major axis of 0.98 AU (comparable to the inner terrestrial zone between Venus, Earth at 1.00 AU, and Mars at 1.52 AU). Its mean orbital velocity is approximately 39 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.139 carries the world between 0.8438 AU at periapsis and 1.1162 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 766 K (+493°C / +919°F) and receiving 57.43 S⊕ (~78,168 W/m²), HD 360 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 360 is classified as a solar-type yellow star of spectral type G8 III with an effective photospheric temperature of 4,770 K, a radius of 10.86 R☉, a mass of 1.69 M☉, an estimated bolometric luminosity of 54.78 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, HD 360 shines at apparent V-band magnitude 5.986 (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: Okayama Astrophysical Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 360 |
| Spectral Type | G8 III |
| Effective Temp (Teff) | 4,770 K |
| Stellar Radius | 10.8600 R☉ |
| Stellar Mass | 1.6900 M☉ |
| Bolometric Luminosity | 54.78 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 5.986 · G: 5.709 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.980000 AU |
| Orbital Period | 273.1 days |
| Mean Orbital Velocity | 39 km/s |
| Orbital Eccentricity (e) | 0.13900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.48 g/cm³ (46.2 km/s vesc) |
| Insolation Flux | 57.4344 S⊕ (~78,168 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 363.800 LY (111.542 pc) |