Kepler-904 b
Astrophysical Synthesis & Habitability Characterization
Kepler-904 b is a confirmed super-earth exoplanet orbiting the star Kepler-904, located approximately 3190.2 light-years (978.13 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0169% across the stellar disk), this world measures 1.77 Earth radii and has a measured mass of 3.78 Earth masses. Combining its mass and radius yields a mean bulk density of 3.76 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 1.21 g⊕ (11.87 m/s²), and an escape velocity of 16.3 km/s.
In its orbital architecture around Kepler-904, Kepler-904 b completes one full revolution every 3.022 Earth days at a semi-major axis of 0.0417 AU (an ultra-close orbit less than one-seventh of Mercury's 0.387 AU distance from the Sun, where strong stellar tidal forces typically induce synchronous rotation). Its mean orbital velocity is approximately 150.1 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 1332 K (+1059°C / +1938°F) and receiving 875.42 S⊕ (~1,191,445 W/m²), Kepler-904 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-904 is classified as a stellar host with an effective photospheric temperature of 6,160 K, a radius of 1.25 R☉, a mass of 1.16 M☉, an estimated bolometric luminosity of 2.019 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.02 Gyr and a metallicity of [Fe/H] = 0.05 dex (near-solar heavy-element abundance). From Earth, Kepler-904 shines at apparent V-band magnitude 14.56 (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-904 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 6,160 K |
| Stellar Radius | 1.2500 R☉ |
| Stellar Mass | 1.1600 M☉ |
| Bolometric Luminosity | 2.019 L☉ |
| Metallicity [Fe/H] | 0.050 dex |
| Stellar Age | 3.020 Gyr |
| Apparent Magnitude | V: 14.560 · G: 14.392 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.041700 AU |
| Orbital Period | 3.022 days |
| Mean Orbital Velocity | 150.1 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.4300° |
| Mean Bulk Density | 3.76 g/cm³ (16.3 km/s vesc) |
| Insolation Flux | 875.4190 S⊕ (~1,191,445 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 3190.200 LY (978.125 pc) |