Kepler-1818 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1818 b is a confirmed super-earth exoplanet orbiting the star Kepler-1818, located approximately 3374.4 light-years (1034.59 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0194% across the stellar disk), this world measures 1.714 Earth radii and has a measured mass of 3.58 Earth masses. Combining its mass and radius yields a mean bulk density of 3.92 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.22 g⊕ (11.96 m/s²), and an escape velocity of 16.2 km/s.
In its orbital architecture around Kepler-1818, Kepler-1818 b completes one full revolution every 4.645 Earth days at a semi-major axis of 0.055 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 128.8 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 1209 K (+936°C / +1717°F) and receiving 504.23 S⊕ (~686,257 W/m²), Kepler-1818 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1818 is classified as a stellar host with an effective photospheric temperature of 6,047 K, a radius of 1.129 R☉, a mass of 1.021 M☉, an estimated bolometric luminosity of 1.529 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.4 Gyr and a metallicity of [Fe/H] = -0.08 dex (near-solar heavy-element abundance). From Earth, Kepler-1818 shines at apparent V-band magnitude 14.514 (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-1818 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,047 K |
| Stellar Radius | 1.1290 R☉ |
| Stellar Mass | 1.0210 M☉ |
| Bolometric Luminosity | 1.529 L☉ |
| Metallicity [Fe/H] | -0.080 dex |
| Stellar Age | 5.400 Gyr |
| Apparent Magnitude | V: 14.514 · G: 14.307 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.055000 AU |
| Orbital Period | 4.645 days |
| Mean Orbital Velocity | 128.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.3100° |
| Mean Bulk Density | 3.92 g/cm³ (16.2 km/s vesc) |
| Insolation Flux | 504.2300 S⊕ (~686,257 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3374.400 LY (1034.590 pc) |