HD 92788 c
Astrophysical Synthesis & Habitability Characterization
HD 92788 c is a confirmed gas giant exoplanet orbiting the star HD 92788, located approximately 113 light-years (34.65 parsecs) from the Solar System. First announced in 2019 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13 Earth radii (1.16 Jupiter radii) and has a measured mass of 1166.436 Earth masses (3.67 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.93 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.9 g⊕ (67.67 m/s²), and an escape velocity of 106 km/s.
In its orbital architecture around HD 92788, HD 92788 c completes one full revolution every 11611.298 Earth days (31.79Julian years) at a semi-major axis of 10.5 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 9.8 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.46, swinging from 5.67 AU at periapsis out to 15.33 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 91 K (-182°C / -296°F) and an incident flux of 0.01 S⊕ (~13 W/m²), surface water and volatile species on HD 92788 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 92788 is classified as a solar-type yellow star of spectral type G6 V with an effective photospheric temperature of 5,744 K, a radius of 1.14 R☉, a mass of 1.15 M☉, an estimated bolometric luminosity of 1.269 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.55 Gyr and a metallicity of [Fe/H] = 0.27 dex (metal-rich relative to the Sun). From Earth, HD 92788 shines at apparent V-band magnitude 7.316 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 92788 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 92788 c sharing its stellar neighborhood alongside HD 92788 b.
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 92788 |
| Spectral Type | G6 V |
| Effective Temp (Teff) | 5,744 K |
| Stellar Radius | 1.1400 R☉ |
| Stellar Mass | 1.1500 M☉ |
| Bolometric Luminosity | 1.269 L☉ |
| Metallicity [Fe/H] | 0.270 dex |
| Stellar Age | 2.550 Gyr |
| Apparent Magnitude | V: 7.316 · G: 7.139 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 10.500000 AU |
| Orbital Period | 11611.298 days |
| Mean Orbital Velocity | 9.8 km/s |
| Orbital Eccentricity (e) | 0.46000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.93 g/cm³ (106 km/s vesc) |
| Insolation Flux | 0.0095 S⊕ (~13 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 113.000 LY (34.654 pc) |