HD 95089 c
Astrophysical Synthesis & Habitability Characterization
HD 95089 c 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 2016 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 13.1 Earth radii (1.17 Jupiter radii) and has a measured mass of 1096.514 Earth masses (3.45 Jupiter masses). Combining its mass and radius yields a mean bulk density of 2.69 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 6.39 g⊕ (62.66 m/s²), and an escape velocity of 102.3 km/s.
In its orbital architecture around HD 95089, HD 95089 c completes one full revolution every 1785 Earth days (4.89Julian years) at a semi-major axis of 3.33 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 20.3 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.284, swinging from 2.3843 AU at periapsis out to 4.2757 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.100 R⊕, HD 95089 c exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
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 c sharing its stellar neighborhood alongside HD 95089 b.
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) | 3.330000 AU |
| Orbital Period | 1785 days |
| Mean Orbital Velocity | 20.3 km/s |
| Orbital Eccentricity (e) | 0.28400 |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 2.69 g/cm³ (102.3 km/s vesc) |
| Insolation Flux | 1.2174 S⊕ (~1,657 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 446.700 LY (136.957 pc) |