Kepler-236 b
Astrophysical Synthesis & Habitability Characterization
Kepler-236 b is a confirmed super-earth exoplanet orbiting the star Kepler-236, located approximately 941.8 light-years (288.76 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0797% across the stellar disk), this world measures 1.57 Earth radii and has a measured mass of 3.09 Earth masses. Combining its mass and radius yields a mean bulk density of 4.4 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.25 g⊕ (12.26 m/s²), and an escape velocity of 15.7 km/s.
In its orbital architecture around Kepler-236, Kepler-236 b completes one full revolution every 8.296 Earth days at a semi-major axis of 0.065 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 85.2 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 469 K (+196°C / +385°F) and receiving 15.63 S⊕ (~21,275 W/m²), Kepler-236 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-236 is classified as a low-mass red dwarf of spectral type M1 V with an effective photospheric temperature of 3,750 K, a radius of 0.51 R☉, a mass of 0.596 M☉, an estimated bolometric luminosity of 0.046 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.91 Gyr and a metallicity of [Fe/H] = -0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-236 shines at apparent V-band magnitude 16.014 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-236 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-236 b sharing its stellar neighborhood alongside Kepler-236 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-236 |
| Spectral Type | M1 V |
| Effective Temp (Teff) | 3,750 K |
| Stellar Radius | 0.5100 R☉ |
| Stellar Mass | 0.5960 M☉ |
| Bolometric Luminosity | 0.046 L☉ |
| Metallicity [Fe/H] | -0.050 dex |
| Stellar Age | 0.910 Gyr |
| Apparent Magnitude | V: 16.014 · G: 15.374 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.065000 AU |
| Orbital Period | 8.296 days |
| Mean Orbital Velocity | 85.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.9500° |
| Mean Bulk Density | 4.4 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 15.6320 S⊕ (~21,275 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 941.800 LY (288.763 pc) |