HD 25015 b
Astrophysical Synthesis & Habitability Characterization
HD 25015 b is a confirmed gas giant exoplanet orbiting the star HD 25015, located approximately 122.1 light-years (37.43 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 12.5 Earth radii (1.12 Jupiter radii) and has a measured mass of 2884.928 Earth masses (9.08 Jupiter masses). Combining its mass and radius yields a mean bulk density of 8.14 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 18.46 g⊕ (181.03 m/s²), and an escape velocity of 169.9 km/s.
In its orbital architecture around HD 25015, HD 25015 b completes one full revolution every 6134.427 Earth days (16.8Julian years) at a semi-major axis of 6.248 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 11.1 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.341, swinging from 4.1174 AU at periapsis out to 8.3786 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⊕ (~14 W/m²), surface water and volatile species on HD 25015 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star HD 25015 is classified as an orange K-type star of spectral type K2 V with an effective photospheric temperature of 5,160 K, a radius of 0.83 R☉, a mass of 0.86 M☉, an estimated bolometric luminosity of 0.438 L☉. Stellar evolution modeling indicates an estimated stellar age of 4 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, HD 25015 shines at apparent V-band magnitude 8.87 (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 25015 |
| Spectral Type | K2 V |
| Effective Temp (Teff) | 5,160 K |
| Stellar Radius | 0.8300 R☉ |
| Stellar Mass | 0.8600 M☉ |
| Bolometric Luminosity | 0.438 L☉ |
| Metallicity [Fe/H] | 0.040 dex |
| Stellar Age | 4.000 Gyr |
| Apparent Magnitude | V: 8.870 · G: 8.599 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 6.248000 AU |
| Orbital Period | 6134.427 days |
| Mean Orbital Velocity | 11.1 km/s |
| Orbital Eccentricity (e) | 0.34100 |
| Orbital Inclination (i) | 32.0460° |
| Mean Bulk Density | 8.14 g/cm³ (169.9 km/s vesc) |
| Insolation Flux | 0.0106 S⊕ (~14 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 122.100 LY (37.433 pc) |