HD 192310 b
Astrophysical Synthesis & Habitability Characterization
HD 192310 b is a confirmed sub-neptune exoplanet orbiting the star HD 192310, located approximately 28.7 light-years (8.8 parsecs) from the Solar System. First announced in 2011 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 4.27 Earth radii (0.38 Jupiter radii) and has a measured mass of 16.9 Earth masses. Combining its mass and radius yields a mean bulk density of 1.2 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.93 g⊕ (9.12 m/s²), and an escape velocity of 22.3 km/s.
In its orbital architecture around HD 192310, HD 192310 b completes one full revolution every 74.72 Earth days at a semi-major axis of 0.32 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 46.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.13 carries the world between 0.2784 AU at periapsis and 0.3616 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 355 K (+82°C / +180°F) and receiving 3.76 S⊕ (~5,117 W/m²), HD 192310 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 192310 is classified as an orange K-type star of spectral type K3V with an effective photospheric temperature of 5,166 K, a radius of 0.8579 R☉, a mass of 0.8 M☉, an estimated bolometric luminosity of 0.47 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.81 Gyr and a metallicity of [Fe/H] = -0.04 dex (near-solar heavy-element abundance). From Earth, HD 192310 shines at apparent V-band magnitude 5.73 (visible to the unaided human eye under dark skies) in the Southern celestial hemisphere. The HD 192310 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 192310 b sharing its stellar neighborhood alongside HD 192310 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 192310 |
| Spectral Type | K3V |
| Effective Temp (Teff) | 5,166 K |
| Stellar Radius | 0.8579 R☉ |
| Stellar Mass | 0.8000 M☉ |
| Bolometric Luminosity | 0.47 L☉ |
| Metallicity [Fe/H] | -0.040 dex |
| Stellar Age | 7.810 Gyr |
| Apparent Magnitude | V: 5.730 · G: 5.477 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.320000 AU |
| Orbital Period | 74.72 days |
| Mean Orbital Velocity | 46.6 km/s |
| Orbital Eccentricity (e) | 0.13000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 1.2 g/cm³ (22.3 km/s vesc) |
| Insolation Flux | 3.7598 S⊕ (~5,117 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 28.700 LY (8.797 pc) |