Kepler-1216 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1216 b is a confirmed super-earth exoplanet orbiting the star Kepler-1216, located approximately 4104.2 light-years (1258.36 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0169% across the stellar disk), this world measures 1.39 Earth radii and has a measured mass of 2.51 Earth masses. Combining its mass and radius yields a mean bulk density of 5.15 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.3 g⊕ (12.75 m/s²), and an escape velocity of 15 km/s.
In its orbital architecture around Kepler-1216, Kepler-1216 b completes one full revolution every 4.37 Earth days at a semi-major axis of 0.0519 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 129.2 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 1191 K (+918°C / +1684°F) and receiving 415.55 S⊕ (~565,568 W/m²), Kepler-1216 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1216 is classified as a stellar host with an effective photospheric temperature of 5,743 K, a radius of 0.98 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 0.937 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.07 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-1216 shines at apparent V-band magnitude 15.262 (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-1216 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,743 K |
| Stellar Radius | 0.9800 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 0.937 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 4.070 Gyr |
| Apparent Magnitude | V: 15.262 · G: 15.107 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.051900 AU |
| Orbital Period | 4.37 days |
| Mean Orbital Velocity | 129.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.5500° |
| Mean Bulk Density | 5.15 g/cm³ (15 km/s vesc) |
| Insolation Flux | 415.5530 S⊕ (~565,568 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4104.200 LY (1258.360 pc) |