Kepler-315 b
Astrophysical Synthesis & Habitability Characterization
Kepler-315 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-315, located approximately 3785.5 light-years (1160.63 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1111% across the stellar disk), this world measures 3.77 Earth radii (0.34 Jupiter radii) and has a measured mass of 13.7 Earth masses. Combining its mass and radius yields a mean bulk density of 1.41 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 0.96 g⊕ (9.41 m/s²), and an escape velocity of 21.3 km/s.
In its orbital architecture around Kepler-315, Kepler-315 b completes one full revolution every 96.101 Earth days at a semi-major axis of 0.402 AU (situated at an orbital separation between Mercury's 0.39 AU and Venus's 0.72 AU). Its mean orbital velocity is approximately 45.5 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 409 K (+136°C / +277°F) and receiving 6.67 S⊕ (~9,083 W/m²), Kepler-315 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-315 is classified as a stellar host with an effective photospheric temperature of 5,796 K, a radius of 1.037 R☉, a mass of 0.831 M☉, an estimated bolometric luminosity of 1.089 L☉. Stellar evolution modeling indicates an estimated stellar age of 12.3 Gyr and a metallicity of [Fe/H] = -0.27 dex (metal-poor relative to the Sun). From Earth, Kepler-315 shines at apparent V-band magnitude 15.546 (faint and requiring research-grade or CCD telescopic photometry) in the Northern celestial hemisphere. The Kepler-315 system is a multi-planet architecture hosting 2 confirmed worlds, with Kepler-315 b sharing its stellar neighborhood alongside Kepler-315 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-315 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,796 K |
| Stellar Radius | 1.0370 R☉ |
| Stellar Mass | 0.8310 M☉ |
| Bolometric Luminosity | 1.089 L☉ |
| Metallicity [Fe/H] | -0.270 dex |
| Stellar Age | 12.300 Gyr |
| Apparent Magnitude | V: 15.546 · G: 15.289 |
| System Architecture | 1 Star, 2 Planets |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.402000 AU |
| Orbital Period | 96.101 days |
| Mean Orbital Velocity | 45.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.2600° |
| Mean Bulk Density | 1.41 g/cm³ (21.3 km/s vesc) |
| Insolation Flux | 6.6740 S⊕ (~9,083 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3785.500 LY (1160.630 pc) |