Kepler-823 b
Astrophysical Synthesis & Habitability Characterization
Kepler-823 b is a confirmed super-earth exoplanet orbiting the star Kepler-823, located approximately 4531.2 light-years (1389.27 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0225% 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-823, Kepler-823 b completes one full revolution every 4.168 Earth days at a semi-major axis of 0.0507 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 132.3 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 1277 K (+1004°C / +1839°F) and receiving 803.35 S⊕ (~1,093,363 W/m²), Kepler-823 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-823 is classified as a stellar host with an effective photospheric temperature of 5,643 K, a radius of 0.96 R☉, a mass of 0.98 M☉, an estimated bolometric luminosity of 0.838 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.47 Gyr and a metallicity of [Fe/H] = 0.06 dex (metal-rich relative to the Sun). From Earth, Kepler-823 shines at apparent V-band magnitude 15.089 (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-823 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,643 K |
| Stellar Radius | 0.9600 R☉ |
| Stellar Mass | 0.9800 M☉ |
| Bolometric Luminosity | 0.838 L☉ |
| Metallicity [Fe/H] | 0.060 dex |
| Stellar Age | 4.470 Gyr |
| Apparent Magnitude | V: 15.089 · G: 14.763 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.050700 AU |
| Orbital Period | 4.168 days |
| Mean Orbital Velocity | 132.3 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 85.0900° |
| Mean Bulk Density | 4.4 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 803.3530 S⊕ (~1,093,363 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4531.200 LY (1389.270 pc) |