Kepler-1809 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1809 b is a confirmed super-earth exoplanet orbiting the star Kepler-1809, located approximately 1335.9 light-years (409.6 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0375% across the stellar disk), this world measures 1.513 Earth radii and has a measured mass of 2.9 Earth masses. Combining its mass and radius yields a mean bulk density of 4.62 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.5 km/s.
In its orbital architecture around Kepler-1809, Kepler-1809 b completes one full revolution every 3.757 Earth days at a semi-major axis of 0.04444 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 128.7 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.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 877 K (+604°C / +1119°F) and receiving 158.20 S⊕ (~215,310 W/m²), Kepler-1809 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1809 is classified as a stellar host with an effective photospheric temperature of 4,901 K, a radius of 0.716 R☉, a mass of 0.807 M☉, an estimated bolometric luminosity of 0.265 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.55 Gyr and a metallicity of [Fe/H] = 0.04 dex (near-solar heavy-element abundance). From Earth, Kepler-1809 shines at apparent V-band magnitude 14.271 (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-1809 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,901 K |
| Stellar Radius | 0.7160 R☉ |
| Stellar Mass | 0.8070 M☉ |
| Bolometric Luminosity | 0.265 L☉ |
| Metallicity [Fe/H] | 0.040 dex |
| Stellar Age | 1.550 Gyr |
| Apparent Magnitude | V: 14.271 · G: 14.138 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.044440 AU |
| Orbital Period | 3.757 days |
| Mean Orbital Velocity | 128.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.7000° |
| Mean Bulk Density | 4.62 g/cm³ (15.5 km/s vesc) |
| Insolation Flux | 158.2000 S⊕ (~215,310 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1335.900 LY (409.602 pc) |