Kepler-1904 b
Astrophysical Synthesis & Habitability Characterization
Kepler-1904 b is a confirmed super-earth exoplanet orbiting the star Kepler-1904, located approximately 883.4 light-years (270.85 parsecs) from the Solar System. First announced in 2021 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0657% across the stellar disk), this world measures 1.39 Earth radii and has a measured mass of 2.51 Earth masses. Combining its mass and radius yields a mean bulk density of 5.15 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.3 g⊕ (12.75 m/s²), and an escape velocity of 15 km/s.
In its orbital architecture around Kepler-1904, Kepler-1904 b completes one full revolution every 4.577 Earth days at a semi-major axis of 0.0436 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 103.6 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 567 K (+294°C / +561°F) and receiving 24.38 S⊕ (~33,181 W/m²), Kepler-1904 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-1904 is classified as a stellar host with an effective photospheric temperature of 3,805 K, a radius of 0.497 R☉, a mass of 0.526 M☉, an estimated bolometric luminosity of 0.046 L☉. Stellar evolution modeling indicates an estimated stellar age of 5.83 Gyr and a metallicity of [Fe/H] = -0.1 dex (near-solar heavy-element abundance). From Earth, Kepler-1904 shines at apparent V-band magnitude 16.367 (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-1904 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 3,805 K |
| Stellar Radius | 0.4970 R☉ |
| Stellar Mass | 0.5260 M☉ |
| Bolometric Luminosity | 0.046 L☉ |
| Metallicity [Fe/H] | -0.100 dex |
| Stellar Age | 5.830 Gyr |
| Apparent Magnitude | V: 16.367 · G: 15.742 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.043600 AU |
| Orbital Period | 4.577 days |
| Mean Orbital Velocity | 103.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 89.4800° |
| Mean Bulk Density | 5.15 g/cm³ (15 km/s vesc) |
| Insolation Flux | 24.3800 S⊕ (~33,181 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 883.400 LY (270.854 pc) |