Kepler-1447 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1447 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1447, located approximately 2903.8 light-years (890.3 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0783% across the stellar disk), this world measures 2.9 Earth radii and has a measured mass of 8.75 Earth masses. Combining its mass and radius yields a mean bulk density of 1.98 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.04 g⊕ (10.2 m/s²), and an escape velocity of 19.4 km/s.
In its orbital architecture around Kepler-1447, Kepler-1447 b completes one full revolution every 56.675 Earth days at a semi-major axis of 0.2836 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 54.4 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 522 K (+249°C / +480°F) and receiving 10.35 S⊕ (~14,085 W/m²), Kepler-1447 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1447 is classified as a stellar host with an effective photospheric temperature of 5,722 K, a radius of 0.95 R☉, a mass of 0.97 M☉, an estimated bolometric luminosity of 0.868 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.17 Gyr and a metallicity of [Fe/H] = -0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-1447 shines at apparent V-band magnitude 14.747 (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-1447 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,722 K |
| Stellar Radius | 0.9500 R☉ |
| Stellar Mass | 0.9700 M☉ |
| Bolometric Luminosity | 0.868 L☉ |
| Metallicity [Fe/H] | -0.030 dex |
| Stellar Age | 4.170 Gyr |
| Apparent Magnitude | V: 14.747 · G: 14.664 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.283600 AU |
| Orbital Period | 56.675 days |
| Mean Orbital Velocity | 54.4 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4400° |
| Mean Bulk Density | 1.98 g/cm³ (19.4 km/s vesc) |
| Insolation Flux | 10.3490 S⊕ (~14,085 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2903.800 LY (890.296 pc) |