Kepler-290 c
Astrophysical Synthesis & Habitability Characterization
Kepler-290 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-290, located approximately 2265.6 light-years (694.63 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.111% across the stellar disk), this world measures 2.7 Earth radii and has a measured mass of 7.75 Earth masses. Combining its mass and radius yields a mean bulk density of 2.17 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.06 g⊕ (10.4 m/s²), and an escape velocity of 19 km/s.
In its orbital architecture around Kepler-290, Kepler-290 c completes one full revolution every 36.77 Earth days at a semi-major axis of 0.205 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 60.7 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 437 K (+164°C / +327°F) and receiving 6.60 S⊕ (~8,977 W/m²), Kepler-290 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-290 is classified as a stellar host with an effective photospheric temperature of 5,147 K, a radius of 0.743 R☉, a mass of 0.756 M☉, an estimated bolometric luminosity of 0.348 L☉. Stellar evolution modeling indicates an estimated stellar age of 1.1 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, Kepler-290 shines at apparent V-band magnitude 15.775 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-290 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-290 c sharing its stellar neighborhood alongside Kepler-290 d, Kepler-290 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-290 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,147 K |
| Stellar Radius | 0.7430 R☉ |
| Stellar Mass | 0.7560 M☉ |
| Bolometric Luminosity | 0.348 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 1.100 Gyr |
| Apparent Magnitude | V: 15.775 · G: 15.565 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.205000 AU |
| Orbital Period | 36.77 days |
| Mean Orbital Velocity | 60.7 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4400° |
| Mean Bulk Density | 2.17 g/cm³ (19 km/s vesc) |
| Insolation Flux | 6.5960 S⊕ (~8,977 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2265.600 LY (694.627 pc) |