Kepler-1268 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1268 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1268, located approximately 6003.8 light-years (1840.77 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0292% across the stellar disk), this world measures 2.03 Earth radii and has a measured mass of 4.78 Earth masses. Combining its mass and radius yields a mean bulk density of 3.15 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.16 g⊕ (11.38 m/s²), and an escape velocity of 17.2 km/s.
In its orbital architecture around Kepler-1268, Kepler-1268 b completes one full revolution every 40.99 Earth days at a semi-major axis of 0.2383 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 63.2 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 627 K (+354°C / +669°F) and receiving 40.65 S⊕ (~55,327 W/m²), Kepler-1268 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1268 is classified as a stellar host with an effective photospheric temperature of 5,904 K, a radius of 1.09 R☉, a mass of 1.06 M☉, an estimated bolometric luminosity of 1.295 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.27 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-1268 shines at apparent V-band magnitude 15.484 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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-1268 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,904 K |
| Stellar Radius | 1.0900 R☉ |
| Stellar Mass | 1.0600 M☉ |
| Bolometric Luminosity | 1.295 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 4.270 Gyr |
| Apparent Magnitude | V: 15.484 · G: 15.222 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.238300 AU |
| Orbital Period | 40.99 days |
| Mean Orbital Velocity | 63.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9400° |
| Mean Bulk Density | 3.15 g/cm³ (17.2 km/s vesc) |
| Insolation Flux | 40.6520 S⊕ (~55,327 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 6003.800 LY (1840.770 pc) |