KIC 8540376 c
Astrophysical Synthesis & Habitability Characterization
KIC 8540376 c is a confirmed sub-neptune exoplanet orbiting the star KOI-7892, located approximately 3497.4 light-years (1072.3 parsecs) from the Solar System. First announced in 2015 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0305% across the stellar disk), this world measures 2.4 Earth radii and has a measured mass of 6.35 Earth masses. Combining its mass and radius yields a mean bulk density of 2.53 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.1 g⊕ (10.79 m/s²), and an escape velocity of 18.2 km/s.
In its orbital architecture around KOI-7892, KIC 8540376 c completes one full revolution every 75.2 Earth days.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 2.400 R⊕, KIC 8540376 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 KOI-7892 is classified as a stellar host with an effective photospheric temperature of 6,474 K, a radius of 1.26 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 2.502 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.16 dex (metal-poor relative to the Sun). From Earth, KOI-7892 shines at apparent V-band magnitude 14.411 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The KOI-7892 system is a multi-planet architecture hosting 3 confirmed worlds, with KIC 8540376 c sharing its stellar neighborhood alongside Kepler-457 d, KIC 8540376 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: Kepler · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | KOI-7892 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,474 K |
| Stellar Radius | 1.2600 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 2.502 L☉ |
| Metallicity [Fe/H] | -0.160 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 14.411 · G: 14.217 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | — |
| Orbital Period | 75.2 days |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | 89.7010° |
| Mean Bulk Density | 2.53 g/cm³ (18.2 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3497.400 LY (1072.300 pc) |