HD 75302 b
Astrophysical Synthesis & Habitability Characterization
HD 75302 b is a confirmed gas giant exoplanet orbiting the star HD 75302, located approximately 98.9 light-years (30.33 parsecs) from the Solar System. First announced in 2023 by La Silla Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.8 Earth radii (1.14 Jupiter radii) and has a measured mass of 1716.273 Earth masses (5.4 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.51 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 10.48 g⊕ (102.77 m/s²), and an escape velocity of 129.5 km/s.
In its orbital architecture around HD 75302, HD 75302 b completes one full revolution every 4356 Earth days (11.93Julian years) at a semi-major axis of 5.3 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 13.2 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.39, swinging from 3.233 AU at periapsis out to 7.367 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
❄️ Thermal Regime (Cryogenic Zone): With an equilibrium temperature of 116 K (-157°C / -251°F) and an incident flux of 0.03 S⊕ (~41 W/m²), surface water and volatile species on HD 75302 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 75302 is classified as a solar-type yellow star of spectral type G5 V with an effective photospheric temperature of 5,697 K, a radius of 0.9409 R☉, a mass of 1.06 M☉, an estimated bolometric luminosity of 0.837 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.1 Gyr and a metallicity of [Fe/H] = 0.086 dex (metal-rich relative to the Sun). From Earth, HD 75302 shines at apparent V-band magnitude 7.45 (accessible to binoculars and small amateur telescopes) in the Northern 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 75302 |
| Spectral Type | G5 V |
| Effective Temp (Teff) | 5,697 K |
| Stellar Radius | 0.9409 R☉ |
| Stellar Mass | 1.0600 M☉ |
| Bolometric Luminosity | 0.837 L☉ |
| Metallicity [Fe/H] | 0.086 dex |
| Stellar Age | 2.100 Gyr |
| Apparent Magnitude | V: 7.450 · G: 7.283 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 5.300000 AU |
| Orbital Period | 4356 days |
| Mean Orbital Velocity | 13.2 km/s |
| Orbital Eccentricity (e) | 0.39000 |
| Orbital Inclination (i) | 29.0000° |
| Mean Bulk Density | 4.51 g/cm³ (129.5 km/s vesc) |
| Insolation Flux | 0.0299 S⊕ (~41 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 98.900 LY (30.329 pc) |