Kepler-293 c
Astrophysical Synthesis & Habitability Characterization
Kepler-293 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-293, located approximately 3178.8 light-years (974.63 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1346% across the stellar disk), this world measures 3.83 Earth radii (0.34 Jupiter radii) and has a measured mass of 14 Earth masses. Combining its mass and radius yields a mean bulk density of 1.37 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.95 g⊕ (9.32 m/s²), and an escape velocity of 21.4 km/s.
In its orbital architecture around Kepler-293, Kepler-293 c completes one full revolution every 54.156 Earth days at a semi-major axis of 0.286 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 57.5 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 466 K (+193°C / +379°F) and receiving 7.29 S⊕ (~9,918 W/m²), Kepler-293 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-293 is classified as a stellar host with an effective photospheric temperature of 5,804 K, a radius of 0.957 R☉, a mass of 0.934 M☉, an estimated bolometric luminosity of 0.932 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.32 Gyr and a metallicity of [Fe/H] = 0.1 dex (metal-rich relative to the Sun). From Earth, Kepler-293 shines at apparent V-band magnitude 15.452 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-293 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-293 c sharing its stellar neighborhood alongside Kepler-293 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-293 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,804 K |
| Stellar Radius | 0.9570 R☉ |
| Stellar Mass | 0.9340 M☉ |
| Bolometric Luminosity | 0.932 L☉ |
| Metallicity [Fe/H] | 0.100 dex |
| Stellar Age | 1.320 Gyr |
| Apparent Magnitude | V: 15.452 · G: 15.333 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.286000 AU |
| Orbital Period | 54.156 days |
| Mean Orbital Velocity | 57.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.7800° |
| Mean Bulk Density | 1.37 g/cm³ (21.4 km/s vesc) |
| Insolation Flux | 7.2870 S⊕ (~9,918 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3178.800 LY (974.633 pc) |