HD 95127 b
Astrophysical Synthesis & Habitability Characterization
HD 95127 b is a confirmed gas giant exoplanet orbiting the star HD 95127, located approximately 2206.7 light-years (676.58 parsecs) from the Solar System. First announced in 2015 by McDonald Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 12.4 Earth radii (1.11 Jupiter radii) and has a measured mass of 3378.533 Earth masses (10.63 Jupiter masses). Combining its mass and radius yields a mean bulk density of 9.77 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 21.97 g⊕ (215.45 m/s²), and an escape velocity of 184.6 km/s.
In its orbital architecture around HD 95127, HD 95127 b completes one full revolution every 482 Earth days (1.32Julian years) at a semi-major axis of 1.28 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 28.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.11 carries the world between 1.1392 AU at periapsis and 1.4208 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1151 K (+878°C / +1612°F) and receiving 116.30 S⊕ (~158,284 W/m²), HD 95127 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 95127 is classified as an orange K-type star of spectral type K0 with an effective photospheric temperature of 4,218 K, a radius of 41.01 R☉, a mass of 3.7 M☉, an estimated bolometric luminosity of 477.635 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.5 Gyr and a metallicity of [Fe/H] = -0.18 dex (metal-poor relative to the Sun). From Earth, HD 95127 shines at apparent V-band magnitude 8.15 (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: McDonald Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 95127 |
| Spectral Type | K0 |
| Effective Temp (Teff) | 4,218 K |
| Stellar Radius | 41.0100 R☉ |
| Stellar Mass | 3.7000 M☉ |
| Bolometric Luminosity | 477.635 L☉ |
| Metallicity [Fe/H] | -0.180 dex |
| Stellar Age | 5.500 Gyr |
| Apparent Magnitude | V: 8.150 · G: 7.721 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.280000 AU |
| Orbital Period | 482 days |
| Mean Orbital Velocity | 28.9 km/s |
| Orbital Eccentricity (e) | 0.11000 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 9.77 g/cm³ (184.6 km/s vesc) |
| Insolation Flux | 116.3001 S⊕ (~158,284 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2206.700 LY (676.579 pc) |