Kepler-975 c
Astrophysical Synthesis & Habitability Characterization
Kepler-975 c is a confirmed gas giant exoplanet orbiting the star Kepler-975, located approximately 1389.7 light-years (426.09 parsecs) from the Solar System. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.3456% across the stellar disk), this world measures 10.69 Earth radii (0.95 Jupiter radii) and has a measured mass of 80.2 Earth masses (0.25 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.36 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.7 g⊕ (6.86 m/s²), and an escape velocity of 30.6 km/s.
In its orbital architecture around Kepler-975, Kepler-975 c completes one full revolution every 5.058 Earth days at a semi-major axis of 0.0567 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 121.9 km/s (compared to Earth's 29.8 km/s). The orbit is modeled as circular (e = 0.00), maintaining a constant stellar distance throughout its year.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 1168 K (+895°C / +1643°F) and receiving 439.80 S⊕ (~598,568 W/m²), Kepler-975 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-975 is classified as a stellar host with an effective photospheric temperature of 4,883 K, a radius of 1.667 R☉, a mass of 0.951 M☉, an estimated bolometric luminosity of 1.417 L☉. Stellar evolution modeling indicates an estimated stellar age of 13.9 Gyr and a metallicity of [Fe/H] = 0.56 dex (metal-rich relative to the Sun). From Earth, Kepler-975 shines at apparent V-band magnitude 14.633 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-975 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-975 c sharing its stellar neighborhood alongside Kepler-975 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 | Kepler-975 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,883 K |
| Stellar Radius | 1.6670 R☉ |
| Stellar Mass | 0.9510 M☉ |
| Bolometric Luminosity | 1.417 L☉ |
| Metallicity [Fe/H] | 0.560 dex |
| Stellar Age | 13.900 Gyr |
| Apparent Magnitude | V: 14.633 · G: 14.452 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.056700 AU |
| Orbital Period | 5.058 days |
| Mean Orbital Velocity | 121.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.0100° |
| Mean Bulk Density | 0.36 g/cm³ (30.6 km/s vesc) |
| Insolation Flux | 439.8000 S⊕ (~598,568 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1389.700 LY (426.088 pc) |