Kepler-898 b
Astrophysical Synthesis & Habitability Characterization
Kepler-898 b is a confirmed super-earth exoplanet orbiting the star Kepler-898, located approximately 1581.5 light-years (484.89 parsecs) from the Solar System. First announced in 2016 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.0485% across the stellar disk), this world measures 1.49 Earth radii and has a measured mass of 2.83 Earth masses. Combining its mass and radius yields a mean bulk density of 4.72 g/cm³ (a terrestrial silicate-iron composition comparable to Earth (5.51 g/cm³)), a surface gravity of 1.27 g⊕ (12.45 m/s²), and an escape velocity of 15.4 km/s.
In its orbital architecture around Kepler-898, Kepler-898 b completes one full revolution every 5.871 Earth days at a semi-major axis of 0.0545 AU (orbiting interior to Mercury's 0.387 AU benchmark in the Solar System). Its mean orbital velocity is approximately 101 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 616 K (+343°C / +649°F) and receiving 37.11 S⊕ (~50,507 W/m²), Kepler-898 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-898 is classified as a stellar host with an effective photospheric temperature of 4,223 K, a radius of 0.62 R☉, a mass of 0.65 M☉, an estimated bolometric luminosity of 0.11 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.98 Gyr and a metallicity of [Fe/H] = -0.06 dex (near-solar heavy-element abundance). From Earth, Kepler-898 shines at apparent V-band magnitude 16.695 (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-898 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 4,223 K |
| Stellar Radius | 0.6200 R☉ |
| Stellar Mass | 0.6500 M☉ |
| Bolometric Luminosity | 0.11 L☉ |
| Metallicity [Fe/H] | -0.060 dex |
| Stellar Age | 3.980 Gyr |
| Apparent Magnitude | V: 16.695 · G: 15.939 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.054500 AU |
| Orbital Period | 5.871 days |
| Mean Orbital Velocity | 101 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 87.3500° |
| Mean Bulk Density | 4.72 g/cm³ (15.4 km/s vesc) |
| Insolation Flux | 37.1100 S⊕ (~50,507 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1581.500 LY (484.891 pc) |