KOI-94 c
Astrophysical Synthesis & Habitability Characterization
KOI-94 c is a confirmed sub-neptune exoplanet orbiting the star KOI-94, located approximately 1555.9 light-years (477.05 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0679% across the stellar disk), this world measures 4.32 Earth radii (0.39 Jupiter radii) and has a measured mass of 15.6 Earth masses. Combining its mass and radius yields a mean bulk density of 1.07 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.84 g⊕ (8.24 m/s²), and an escape velocity of 21.3 km/s.
In its orbital architecture around KOI-94, KOI-94 c completes one full revolution every 10.424 Earth days at a semi-major axis of 0.1013 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 105.7 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.43, swinging from 0.0577 AU at periapsis out to 0.1449 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1012 K (+739°C / +1362°F) and receiving 268.22 S⊕ (~365,046 W/m²), KOI-94 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star KOI-94 is classified as a stellar host with an effective photospheric temperature of 6,182 K, a radius of 1.52 R☉, a mass of 1.277 M☉, an estimated bolometric luminosity of 3.028 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.16 Gyr and a metallicity of [Fe/H] = 0.023 dex (near-solar heavy-element abundance). From Earth, KOI-94 shines at apparent V-band magnitude 12.314 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The KOI-94 system is a multi-planet architecture hosting 4 confirmed worlds, with KOI-94 c sharing its stellar neighborhood alongside KOI-94 b, KOI-94 d, KOI-94 e.
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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | KOI-94 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,182 K |
| Stellar Radius | 1.5200 R☉ |
| Stellar Mass | 1.2770 M☉ |
| Bolometric Luminosity | 3.028 L☉ |
| Metallicity [Fe/H] | 0.023 dex |
| Stellar Age | 3.160 Gyr |
| Apparent Magnitude | V: 12.314 · G: 12.188 |
| System Architecture | 2 Stars, 4 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.101300 AU |
| Orbital Period | 10.424 days |
| Mean Orbital Velocity | 105.7 km/s |
| Orbital Eccentricity (e) | 0.43000 |
| Orbital Inclination (i) | 88.3600° |
| Mean Bulk Density | 1.07 g/cm³ (21.3 km/s vesc) |
| Insolation Flux | 268.2190 S⊕ (~365,046 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1555.900 LY (477.052 pc) |