HD 50499 c
Astrophysical Synthesis & Habitability Characterization
HD 50499 c is a confirmed gas giant exoplanet orbiting the star HD 50499, located approximately 151 light-years (46.29 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 13.2 Earth radii (1.18 Jupiter radii) and has a measured mass of 931.242 Earth masses (2.93 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.23 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 5.34 g⊕ (52.37 m/s²), and an escape velocity of 94 km/s.
In its orbital architecture around HD 50499, HD 50499 c completes one full revolution every 8619.9 Earth days (23.6Julian years) at a semi-major axis of 9.02 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 11.4 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 117 K (-156°C / -249°F) and an incident flux of 0.03 S⊕ (~40 W/m²), surface water and volatile species on HD 50499 c would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 50499 is classified as a solar-type yellow star of spectral type G1 V with an effective photospheric temperature of 6,099 K, a radius of 1.42 R☉, a mass of 1.31 M☉, an estimated bolometric luminosity of 2.503 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.4 Gyr and a metallicity of [Fe/H] = 0.38 dex (metal-rich relative to the Sun). From Earth, HD 50499 shines at apparent V-band magnitude 7.21 (accessible to binoculars and small amateur telescopes) in the Southern celestial hemisphere. The HD 50499 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 50499 c sharing its stellar neighborhood alongside HD 50499 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 50499 |
| Spectral Type | G1 V |
| Effective Temp (Teff) | 6,099 K |
| Stellar Radius | 1.4200 R☉ |
| Stellar Mass | 1.3100 M☉ |
| Bolometric Luminosity | 2.503 L☉ |
| Metallicity [Fe/H] | 0.380 dex |
| Stellar Age | 2.400 Gyr |
| Apparent Magnitude | V: 7.210 · G: 7.056 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 9.020000 AU |
| Orbital Period | 8619.9 days |
| Mean Orbital Velocity | 11.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.23 g/cm³ (94 km/s vesc) |
| Insolation Flux | 0.0292 S⊕ (~40 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 151.000 LY (46.285 pc) |