Kepler-487 c
Astrophysical Synthesis & Habitability Characterization
Kepler-487 c is a confirmed sub-neptune exoplanet orbiting the star Kepler-487, located approximately 2845.2 light-years (872.34 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.078% across the stellar disk), this world measures 2.68 Earth radii and has a measured mass of 7.65 Earth masses. Combining its mass and radius yields a mean bulk density of 2.19 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.07 g⊕ (10.49 m/s²), and an escape velocity of 18.9 km/s.
In its orbital architecture around Kepler-487, Kepler-487 c completes one full revolution every 38.652 Earth days at a semi-major axis of 0.21864 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 61.5 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 487 K (+214°C / +417°F) and receiving 15.04 S⊕ (~20,467 W/m²), Kepler-487 c orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-487 is classified as a stellar host with an effective photospheric temperature of 5,444 K, a radius of 0.88 R☉, a mass of 0.91 M☉, an estimated bolometric luminosity of 0.61 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.62 Gyr and a metallicity of [Fe/H] = 0 dex (near-solar heavy-element abundance). From Earth, Kepler-487 shines at apparent V-band magnitude 14.882 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-487 system is a multi-planet architecture hosting 3 confirmed worlds, with Kepler-487 c sharing its stellar neighborhood alongside Kepler-487 d, Kepler-487 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-487 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,444 K |
| Stellar Radius | 0.8800 R☉ |
| Stellar Mass | 0.9100 M☉ |
| Bolometric Luminosity | 0.61 L☉ |
| Metallicity [Fe/H] | 0.000 dex |
| Stellar Age | 5.620 Gyr |
| Apparent Magnitude | V: 14.882 · G: 15.065 |
| System Architecture | 1 Star, 3 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.218640 AU |
| Orbital Period | 38.652 days |
| Mean Orbital Velocity | 61.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.9600° |
| Mean Bulk Density | 2.19 g/cm³ (18.9 km/s vesc) |
| Insolation Flux | 15.0380 S⊕ (~20,467 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 2845.200 LY (872.343 pc) |