Kepler-249 d
Astrophysical Synthesis & Habitability Characterization
Kepler-249 d is a confirmed super-earth exoplanet orbiting the star Kepler-249, located approximately 621 light-years (190.4 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0892% 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-249, Kepler-249 d completes one full revolution every 15.368 Earth days at a semi-major axis of 0.097 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 68.7 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.
ℹ️ Thermal & Atmospheric Regime: Current photometric and spectroscopic constraints for Kepler-249 d place it outside the conservative habitable zone definition pending further atmospheric characterization.
The host star Kepler-249 is classified as a low-mass red dwarf of spectral type M2 V with an effective photospheric temperature of 3,568 K, a radius of 0.482 R☉, a mass of 0.5102 M☉, an estimated bolometric luminosity of 0.034 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.86 Gyr and a metallicity of [Fe/H] = -0.34 dex (metal-poor relative to the Sun). From Earth, Kepler-249 shines at apparent V-band magnitude 16.37 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-249 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-249 d sharing its stellar neighborhood alongside Kepler-249 b, Kepler-249 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-249 |
| Spectral Type | M2 V |
| Effective Temp (Teff) | 3,568 K |
| Stellar Radius | 0.4820 R☉ |
| Stellar Mass | 0.5102 M☉ |
| Bolometric Luminosity | 0.034 L☉ |
| Metallicity [Fe/H] | -0.340 dex |
| Stellar Age | 3.860 Gyr |
| Apparent Magnitude | V: 16.370 · G: 15.231 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.097000 AU |
| Orbital Period | 15.368 days |
| Mean Orbital Velocity | 68.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.8600° |
| Mean Bulk Density | 4.4 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 4.4740 S⊕ (~6,089 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 621.000 LY (190.401 pc) |