Kepler-1641 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1641 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-1641, located approximately 2806.1 light-years (860.37 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0517% across the stellar disk), this world measures 2.95 Earth radii and has a measured mass of 9.01 Earth masses. Combining its mass and radius yields a mean bulk density of 1.94 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.04 g⊕ (10.2 m/s²), and an escape velocity of 19.5 km/s.
In its orbital architecture around Kepler-1641, Kepler-1641 c completes one full revolution every 32.657 Earth days at a semi-major axis of 0.2065 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 68.8 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 767 K (+494°C / +921°F) and receiving 42.15 S⊕ (~57,359 W/m²), Kepler-1641 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1641 is classified as a stellar host with an effective photospheric temperature of 6,152 K, a radius of 1.19 R☉, a mass of 1.12 M☉, an estimated bolometric luminosity of 1.82 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.02 Gyr and a metallicity of [Fe/H] = -0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-1641 shines at apparent V-band magnitude 14.49 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1641 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1641 c sharing its stellar neighborhood alongside Kepler-1641 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-1641 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,152 K |
| Stellar Radius | 1.1900 R☉ |
| Stellar Mass | 1.1200 M☉ |
| Bolometric Luminosity | 1.82 L☉ |
| Metallicity [Fe/H] | -0.020 dex |
| Stellar Age | 3.020 Gyr |
| Apparent Magnitude | V: 14.490 · G: 14.223 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.206500 AU |
| Orbital Period | 32.657 days |
| Mean Orbital Velocity | 68.8 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9900° |
| Mean Bulk Density | 1.94 g/cm³ (19.5 km/s vesc) |
| Insolation Flux | 42.1450 S⊕ (~57,359 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2806.100 LY (860.370 pc) |