Kepler-1859 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1859 c is a confirmed super-earth exoplanet orbiting the star Kepler-1859, located approximately 4342 light-years (1331.25 parsecs) from the Solar System. First announced in 2023 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0152% across the stellar disk), this world measures 1.66 Earth radii and has a measured mass of 3.39 Earth masses. Combining its mass and radius yields a mean bulk density of 4.09 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.23 g⊕ (12.06 m/s²), and an escape velocity of 16 km/s.
In its orbital architecture around Kepler-1859, Kepler-1859 c completes one full revolution every 3.596 Earth days at a semi-major axis of 0.0473 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 143.1 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 1327 K (+1054°C / +1929°F) and receiving 732.82 S⊕ (~997,368 W/m²), Kepler-1859 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1859 is classified as a stellar host with an effective photospheric temperature of 5,887 K, a radius of 1.235 R☉, a mass of 1.09 M☉, an estimated bolometric luminosity of 1.644 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.5 Gyr and a metallicity of [Fe/H] = 0.16 dex (metal-rich relative to the Sun). From Earth, Kepler-1859 shines at apparent V-band magnitude 15.178 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1859 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1859 c sharing its stellar neighborhood alongside Kepler-1859 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-1859 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,887 K |
| Stellar Radius | 1.2350 R☉ |
| Stellar Mass | 1.0900 M☉ |
| Bolometric Luminosity | 1.644 L☉ |
| Metallicity [Fe/H] | 0.160 dex |
| Stellar Age | 2.500 Gyr |
| Apparent Magnitude | V: 15.178 · G: 15.109 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.047300 AU |
| Orbital Period | 3.596 days |
| Mean Orbital Velocity | 143.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 83.3100° |
| Mean Bulk Density | 4.09 g/cm³ (16 km/s vesc) |
| Insolation Flux | 732.8200 S⊕ (~997,368 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 4342.000 LY (1331.250 pc) |