Kepler-913 b
Astrophysical Synthesis & Habitability Characterization
Kepler-913 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-913, located approximately 3234.2 light-years (991.62 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0959% across the stellar disk), this world measures 2.06 Earth radii and has a measured mass of 4.9 Earth masses. Combining its mass and radius yields a mean bulk density of 3.09 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.15 g⊕ (11.28 m/s²), and an escape velocity of 17.3 km/s.
In its orbital architecture around Kepler-913, Kepler-913 b completes one full revolution every 10.297 Earth days at a semi-major axis of 0.1009 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 106.6 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 1129 K (+856°C / +1573°F) and receiving 58.90 S⊕ (~80,163 W/m²), Kepler-913 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-913 is classified as a stellar host with an effective photospheric temperature of 4,687 K, a radius of 0.61 R☉, a mass of 0.63 M☉, an estimated bolometric luminosity of 0.161 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.62 Gyr and a metallicity of [Fe/H] = -0.52 dex (metal-poor relative to the Sun). From Earth, Kepler-913 shines at apparent V-band magnitude 15.522 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-913 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-913 b sharing its stellar neighborhood alongside Kepler-913 c.
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-913 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,687 K |
| Stellar Radius | 0.6100 R☉ |
| Stellar Mass | 0.6300 M☉ |
| Bolometric Luminosity | 0.161 L☉ |
| Metallicity [Fe/H] | -0.520 dex |
| Stellar Age | 5.620 Gyr |
| Apparent Magnitude | V: 15.522 · G: 15.739 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.100900 AU |
| Orbital Period | 10.297 days |
| Mean Orbital Velocity | 106.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4000° |
| Mean Bulk Density | 3.09 g/cm³ (17.3 km/s vesc) |
| Insolation Flux | 58.9000 S⊕ (~80,163 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3234.200 LY (991.618 pc) |