Kepler-1181 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1181 b is a confirmed super-earth exoplanet orbiting the star Kepler-1181, located approximately 3060.7 light-years (938.42 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0123% 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-1181, Kepler-1181 b completes one full revolution every 4.893 Earth days at a semi-major axis of 0.0621 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 138.1 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 1374 K (+1101°C / +2014°F) and receiving 831.14 S⊕ (~1,131,186 W/m²), Kepler-1181 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1181 is classified as a stellar host with an effective photospheric temperature of 6,176 K, a radius of 1.3 R☉, a mass of 1.17 M☉, an estimated bolometric luminosity of 2.206 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.24 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-1181 shines at apparent V-band magnitude 13.549 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1181 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1181 b sharing its stellar neighborhood alongside Kepler-1181 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-1181 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,176 K |
| Stellar Radius | 1.3000 R☉ |
| Stellar Mass | 1.1700 M☉ |
| Bolometric Luminosity | 2.206 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 3.240 Gyr |
| Apparent Magnitude | V: 13.549 · G: 13.455 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.062100 AU |
| Orbital Period | 4.893 days |
| Mean Orbital Velocity | 138.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.8200° |
| Mean Bulk Density | 4.4 g/cm³ (15.7 km/s vesc) |
| Insolation Flux | 831.1430 S⊕ (~1,131,186 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3060.700 LY (938.417 pc) |