Kepler-1365 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1365 c is a confirmed terrestrial exoplanet orbiting the star Kepler-1365, located approximately 2740.1 light-years (840.13 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0049% across the stellar disk), this world measures 0.8 Earth radii and has a measured mass of 0.437 Earth masses. Combining its mass and radius yields a mean bulk density of 4.71 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 0.68 g⊕ (6.67 m/s²), and an escape velocity of 8.3 km/s.
In its orbital architecture around Kepler-1365, Kepler-1365 c completes one full revolution every 4.775 Earth days at a semi-major axis of 0.05701 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 129.9 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 1137 K (+864°C / +1587°F) and receiving 864.04 S⊕ (~1,175,954 W/m²), Kepler-1365 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1365 is classified as a stellar host with an effective photospheric temperature of 5,770 K, a radius of 1.05 R☉, a mass of 1 M☉, an estimated bolometric luminosity of 1.096 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.03 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-1365 shines at apparent V-band magnitude 13.417 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1365 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1365 c sharing its stellar neighborhood alongside Kepler-1365 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-1365 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,770 K |
| Stellar Radius | 1.0500 R☉ |
| Stellar Mass | 1.0000 M☉ |
| Bolometric Luminosity | 1.096 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 6.030 Gyr |
| Apparent Magnitude | V: 13.417 · G: 13.380 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.057010 AU |
| Orbital Period | 4.775 days |
| Mean Orbital Velocity | 129.9 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8200° |
| Mean Bulk Density | 4.71 g/cm³ (8.3 km/s vesc) |
| Insolation Flux | 864.0370 S⊕ (~1,175,954 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2740.100 LY (840.128 pc) |