HD 95089 b
Astrophysical Synthesis & Habitability Characterization
HD 95089 b is a confirmed gas giant exoplanet orbiting the star HD 95089, located approximately 446.7 light-years (136.96 parsecs) from the Solar System. First announced in 2009 by W. M. Keck Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.7 Earth radii (1.22 Jupiter radii) and has a measured mass of 400.466 Earth masses (1.26 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.86 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 2.13 g⊕ (20.89 m/s²), and an escape velocity of 60.5 km/s.
In its orbital architecture around HD 95089, HD 95089 b completes one full revolution every 464.4 Earth days (1.27Julian years) at a semi-major axis of 1.36 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 31.9 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.119 carries the world between 1.1982 AU at periapsis and 1.5218 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 458 K (+185°C / +365°F) and receiving 7.30 S⊕ (~9,934 W/m²), HD 95089 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star HD 95089 is classified as a solar-type yellow star of spectral type G8/K0 IV with an effective photospheric temperature of 4,918 K, a radius of 5.08 R☉, a mass of 1.54 M☉, an estimated bolometric luminosity of 13.545 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.5 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, HD 95089 shines at apparent V-band magnitude 7.92 (accessible to binoculars and small amateur telescopes) in the Northern celestial hemisphere. The HD 95089 system is a multi-planet architecture hosting 2 confirmed worlds, with HD 95089 b sharing its stellar neighborhood alongside HD 95089 c.
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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | HD 95089 |
| Spectral Type | G8/K0 IV |
| Effective Temp (Teff) | 4,918 K |
| Stellar Radius | 5.0800 R☉ |
| Stellar Mass | 1.5400 M☉ |
| Bolometric Luminosity | 13.545 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 2.500 Gyr |
| Apparent Magnitude | V: 7.920 · G: 7.661 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 1.360000 AU |
| Orbital Period | 464.4 days |
| Mean Orbital Velocity | 31.9 km/s |
| Orbital Eccentricity (e) | 0.11900 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 0.86 g/cm³ (60.5 km/s vesc) |
| Insolation Flux | 7.2989 S⊕ (~9,934 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 446.700 LY (136.957 pc) |