Kepler-180 c
Astrophysical Synthesis & Habitability Characterization
Kepler-180 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-180, located approximately 2268.9 light-years (695.65 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0674% across the stellar disk), this world measures 3.01 Earth radii (0.27 Jupiter radii) and has a measured mass of 9.32 Earth masses. Combining its mass and radius yields a mean bulk density of 1.88 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.03 g⊕ (10.1 m/s²), and an escape velocity of 19.7 km/s.
In its orbital architecture around Kepler-180, Kepler-180 c completes one full revolution every 41.886 Earth days at a semi-major axis of 0.229 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 59.5 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 540 K (+267°C / +513°F) and receiving 16.42 S⊕ (~22,352 W/m²), Kepler-180 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-180 is classified as a stellar host with an effective photospheric temperature of 5,731 K, a radius of 1.063 R☉, a mass of 0.95 M☉, an estimated bolometric luminosity of 1.094 L☉. Stellar evolution modeling indicates an estimated stellar age of 9.7 Gyr and a metallicity of [Fe/H] = 0.03 dex (near-solar heavy-element abundance). From Earth, Kepler-180 shines at apparent V-band magnitude 14.488 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-180 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-180 c sharing its stellar neighborhood alongside Kepler-180 b.
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-180 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,731 K |
| Stellar Radius | 1.0630 R☉ |
| Stellar Mass | 0.9500 M☉ |
| Bolometric Luminosity | 1.094 L☉ |
| Metallicity [Fe/H] | 0.030 dex |
| Stellar Age | 9.700 Gyr |
| Apparent Magnitude | V: 14.488 · G: 14.325 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.229000 AU |
| Orbital Period | 41.886 days |
| Mean Orbital Velocity | 59.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.6200° |
| Mean Bulk Density | 1.88 g/cm³ (19.7 km/s vesc) |
| Insolation Flux | 16.4230 S⊕ (~22,352 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2268.900 LY (695.650 pc) |