Kepler-1188 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1188 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-1188, located approximately 5601.7 light-years (1717.48 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0324% across the stellar disk), this world measures 2.08 Earth radii and has a measured mass of 4.98 Earth masses. Combining its mass and radius yields a mean bulk density of 3.05 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.3 km/s.
In its orbital architecture around Kepler-1188, Kepler-1188 b completes one full revolution every 17.137 Earth days at a semi-major axis of 0.135 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 85.7 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 775 K (+502°C / +936°F) and receiving 165.57 S⊕ (~225,345 W/m²), Kepler-1188 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1188 is classified as a stellar host with an effective photospheric temperature of 5,913 K, a radius of 1.06 R☉, a mass of 1.04 M☉, an estimated bolometric luminosity of 1.232 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.17 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-1188 shines at apparent V-band magnitude 14.941 (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-1188 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,913 K |
| Stellar Radius | 1.0600 R☉ |
| Stellar Mass | 1.0400 M☉ |
| Bolometric Luminosity | 1.232 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 4.170 Gyr |
| Apparent Magnitude | V: 14.941 · G: 14.968 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.135000 AU |
| Orbital Period | 17.137 days |
| Mean Orbital Velocity | 85.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9200° |
| Mean Bulk Density | 3.05 g/cm³ (17.3 km/s vesc) |
| Insolation Flux | 165.5730 S⊕ (~225,345 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 5601.700 LY (1717.480 pc) |