Kepler-955 b
Astrophysical Synthesis & Habitability Characterization
Kepler-955 b is a confirmed sub-neptune exoplanet orbiting the star Kepler-955, located approximately 1795.1 light-years (550.38 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.1167% across the stellar disk), this world measures 3.13 Earth radii (0.28 Jupiter radii) and has a measured mass of 9.96 Earth masses. Combining its mass and radius yields a mean bulk density of 1.79 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.02 g⊕ (10 m/s²), and an escape velocity of 20 km/s.
In its orbital architecture around Kepler-955, Kepler-955 b completes one full revolution every 14.532 Earth days at a semi-major axis of 0.1083 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 81.1 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 664 K (+391°C / +736°F) and receiving 33.09 S⊕ (~45,037 W/m²), Kepler-955 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-955 is classified as a stellar host with an effective photospheric temperature of 5,350 K, a radius of 0.84 R☉, a mass of 0.89 M☉, an estimated bolometric luminosity of 0.519 L☉. Stellar evolution modeling indicates an estimated stellar age of 4.37 Gyr and a metallicity of [Fe/H] = 0.02 dex (near-solar heavy-element abundance). From Earth, Kepler-955 shines at apparent V-band magnitude 14.734 (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 | Kepler-955 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,350 K |
| Stellar Radius | 0.8400 R☉ |
| Stellar Mass | 0.8900 M☉ |
| Bolometric Luminosity | 0.519 L☉ |
| Metallicity [Fe/H] | 0.020 dex |
| Stellar Age | 4.370 Gyr |
| Apparent Magnitude | V: 14.734 · G: 14.627 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.108300 AU |
| Orbital Period | 14.532 days |
| Mean Orbital Velocity | 81.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 90.0000° |
| Mean Bulk Density | 1.79 g/cm³ (20 km/s vesc) |
| Insolation Flux | 33.0910 S⊕ (~45,037 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1795.100 LY (550.383 pc) |