Kepler-145 c
Astrophysical Synthesis & Habitability Characterization
Kepler-145 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-145, located approximately 1848.8 light-years (566.85 parsecs) from the Solar System. First announced in 2013 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0458% across the stellar disk), this world measures 4.32 Earth radii (0.39 Jupiter radii) and has a measured mass of 79.4 Earth masses (0.25 Jupiter masses). Combining its mass and radius yields a mean bulk density of 5.43 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 4.25 g⊕ (41.68 m/s²), and an escape velocity of 48 km/s.
In its orbital architecture around Kepler-145, Kepler-145 c completes one full revolution every 42.882 Earth days at a semi-major axis of 0.26244 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 66.6 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.11 carries the world between 0.2336 AU at periapsis and 0.2913 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 709 K (+436°C / +817°F) and receiving 67.19 S⊕ (~91,450 W/m²), Kepler-145 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-145 is classified as a stellar host with an effective photospheric temperature of 6,022 K, a radius of 1.85 R☉, a mass of 1.32 M☉, an estimated bolometric luminosity of 4.038 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.24 Gyr and a metallicity of [Fe/H] = -0.001 dex (near-solar heavy-element abundance). From Earth, Kepler-145 shines at apparent V-band magnitude 11.977 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-145 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-145 c sharing its stellar neighborhood alongside Kepler-145 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-145 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,022 K |
| Stellar Radius | 1.8500 R☉ |
| Stellar Mass | 1.3200 M☉ |
| Bolometric Luminosity | 4.038 L☉ |
| Metallicity [Fe/H] | -0.001 dex |
| Stellar Age | 3.240 Gyr |
| Apparent Magnitude | V: 11.977 · G: 11.875 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.262440 AU |
| Orbital Period | 42.882 days |
| Mean Orbital Velocity | 66.6 km/s |
| Orbital Eccentricity (e) | 0.11000 |
| Orbital Inclination (i) | 89.2900° |
| Mean Bulk Density | 5.43 g/cm³ (48 km/s vesc) |
| Insolation Flux | 67.1930 S⊕ (~91,450 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1848.800 LY (566.850 pc) |