KOI-7913 b
Astrophysical Synthesis & Habitability Characterization
KOI-7913 b is a confirmed sub-neptune exoplanet orbiting the star KOI-7913 A, located approximately 884.8 light-years (271.28 parsecs) from the Solar System. First announced in 2022 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0741% across the stellar disk), this world measures 2.34 Earth radii and has a measured mass of 6.08 Earth masses. Combining its mass and radius yields a mean bulk density of 2.62 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.11 g⊕ (10.89 m/s²), and an escape velocity of 18 km/s.
In its orbital architecture around KOI-7913 A, KOI-7913 b completes one full revolution every 24.279 Earth days at a semi-major axis of 0.1456 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 65.2 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 432 K (+159°C / +318°F) and receiving 8.27 S⊕ (~11,255 W/m²), KOI-7913 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star KOI-7913 A is classified as an orange K-type star of spectral type K6 V with an effective photospheric temperature of 4,324 K, a radius of 0.788 R☉, a mass of 0.76 M☉, an estimated bolometric luminosity of 0.195 L☉. Stellar evolution modeling indicates an estimated stellar age of 0.036 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, KOI-7913 A shines at apparent V-band magnitude 14.23 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere.
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 | KOI-7913 A |
| Spectral Type | K6 V |
| Effective Temp (Teff) | 4,324 K |
| Stellar Radius | 0.7880 R☉ |
| Stellar Mass | 0.7600 M☉ |
| Bolometric Luminosity | 0.195 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 0.036 Gyr |
| Apparent Magnitude | V: 14.230 · G: 14.224 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.145600 AU |
| Orbital Period | 24.279 days |
| Mean Orbital Velocity | 65.2 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.6200° |
| Mean Bulk Density | 2.62 g/cm³ (18 km/s vesc) |
| Insolation Flux | 8.2700 S⊕ (~11,255 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 884.800 LY (271.277 pc) |