Kepler-366 b
Astrophysical Synthesis & Habitability Characterization
Kepler-366 b is a confirmed super-earth exoplanet orbiting the star Kepler-366, located approximately 6054.4 light-years (1856.28 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0163% across the stellar disk), this world measures 1.46 Earth radii and has a measured mass of 2.73 Earth masses. Combining its mass and radius yields a mean bulk density of 4.84 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.28 g⊕ (12.55 m/s²), and an escape velocity of 15.3 km/s.
In its orbital architecture around Kepler-366, Kepler-366 b completes one full revolution every 3.282 Earth days at a semi-major axis of 0.045 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 149.2 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 1326 K (+1053°C / +1927°F) and receiving 1,873.31 S⊕ (~2,549,576 W/m²), Kepler-366 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-366 is classified as a stellar host with an effective photospheric temperature of 6,209 K, a radius of 1.048 R☉, a mass of 1.088 M☉, an estimated bolometric luminosity of 1.465 L☉. Stellar evolution modeling indicates an estimated stellar age of 6.61 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-366 shines at apparent V-band magnitude 14.952 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-366 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-366 b sharing its stellar neighborhood alongside Kepler-366 c.
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-366 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,209 K |
| Stellar Radius | 1.0480 R☉ |
| Stellar Mass | 1.0880 M☉ |
| Bolometric Luminosity | 1.465 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 6.610 Gyr |
| Apparent Magnitude | V: 14.952 · G: 14.790 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.045000 AU |
| Orbital Period | 3.282 days |
| Mean Orbital Velocity | 149.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.5000° |
| Mean Bulk Density | 4.84 g/cm³ (15.3 km/s vesc) |
| Insolation Flux | 1873.3110 S⊕ (~2,549,576 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 6054.400 LY (1856.280 pc) |