HD 102888 b
Astrophysical Synthesis & Habitability Characterization
HD 102888 b is a confirmed gas giant exoplanet orbiting the star HD 102888, located approximately 412.5 light-years (126.48 parsecs) from the Solar System. First announced in 2025 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 1808.444 Earth masses (5.69 Jupiter masses). Combining its mass and radius yields a mean bulk density of 4.75 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 11.04 g⊕ (108.27 m/s²), and an escape velocity of 133 km/s.
In its orbital architecture around HD 102888, HD 102888 b completes one full revolution every 252.06 Earth days at a semi-major axis of 1.05 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 45.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.11 carries the world between 0.9345 AU at periapsis and 1.1655 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 689 K (+416°C / +781°F) and receiving 37.45 S⊕ (~50,971 W/m²), HD 102888 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 102888 is classified as a solar-type yellow star of spectral type G8 III with an effective photospheric temperature of 4,990 K, a radius of 8.6 R☉, a mass of 2.42 M☉, an estimated bolometric luminosity of 41.142 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = 0.07 dex (metal-rich relative to the Sun). From Earth, HD 102888 shines at apparent V-band magnitude 6.48 (accessible to binoculars and small amateur telescopes) 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: La Silla Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 102888 |
| Spectral Type | G8 III |
| Effective Temp (Teff) | 4,990 K |
| Stellar Radius | 8.6000 R☉ |
| Stellar Mass | 2.4200 M☉ |
| Bolometric Luminosity | 41.142 L☉ |
| Metallicity [Fe/H] | 0.070 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 6.480 · G: 6.221 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.050000 AU |
| Orbital Period | 252.06 days |
| Mean Orbital Velocity | 45.3 km/s |
| Orbital Eccentricity (e) | 0.11000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 4.75 g/cm³ (133 km/s vesc) |
| Insolation Flux | 37.4512 S⊕ (~50,971 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 412.500 LY (126.484 pc) |