Kepler-1649 c
Astrophysical Synthesis & Habitability Characterization
Kepler-1649 c is a confirmed terrestrial exoplanet orbiting the star Kepler-1649, located approximately 300.7 light-years (92.19 parsecs) from the Solar System. First announced in 2020 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1759% across the stellar disk), this world measures 1.06 Earth radii and has a measured mass of 1.2 Earth masses. Combining its mass and radius yields a mean bulk density of 5.56 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.07 g⊕ (10.49 m/s²), and an escape velocity of 11.9 km/s.
In its orbital architecture around Kepler-1649, Kepler-1649 c completes one full revolution every 19.535 Earth days at a semi-major axis of 0.0649 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 36.1 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.
✓ Classified as a Temperate Habitable Zone Candidate.
With an estimated equilibrium temperature of 234 K (-39°C / -38°F) and an incident stellar irradiance of 0.75 S⊕ (~1,021 W/m²), Kepler-1649 c orbits within the empirical circumstellar habitable zone where a rocky surface under sufficient atmospheric pressure can maintain liquid surface water.
The host star Kepler-1649 is classified as a stellar host with an effective photospheric temperature of 3,240 K, a radius of 0.2317 R☉, a mass of 0.1977 M☉, an estimated bolometric luminosity of 0.00531 L☉. Stellar evolution modeling indicates a metallicity of [Fe/H] = -0.15 dex (metal-poor relative to the Sun). From Earth, Kepler-1649 shines at apparent V-band magnitude 17.95 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-1649 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-1649 c sharing its stellar neighborhood alongside Kepler-1649 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-1649 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,240 K |
| Stellar Radius | 0.2317 R☉ |
| Stellar Mass | 0.1977 M☉ |
| Bolometric Luminosity | 0.00531 L☉ |
| Metallicity [Fe/H] | -0.150 dex |
| Stellar Age | — |
| Apparent Magnitude | V: 17.950 · G: 16.268 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.064900 AU |
| Orbital Period | 19.535 days |
| Mean Orbital Velocity | 36.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.3390° |
| Mean Bulk Density | 5.56 g/cm³ (11.9 km/s vesc) |
| Insolation Flux | 0.7500 S⊕ (~1,021 W/m²) |
| Habitable Zone Status | ★ Temperate Zone |
| Celestial Distance | 300.700 LY (92.191 pc) |