Kepler-98 b
Astrophysical Synthesis & Habitability Characterization
Kepler-98 b is a confirmed super-earth exoplanet orbiting the star Kepler-98, located approximately 1142.6 light-years (350.32 parsecs) from the Solar System. First announced in 2014 by Kepler using the Transit detection technique (producing an estimated primary transit depth of 0.027% across the stellar disk), this world measures 1.99 Earth radii and has a measured mass of 3.55 Earth masses. Combining its mass and radius yields a mean bulk density of 2.48 g/cm³ (an intermediate density indicative of a deep water-ice mantle or dense volatile envelope), a surface gravity of 0.9 g⊕ (8.83 m/s²), and an escape velocity of 14.9 km/s.
In its orbital architecture around Kepler-98, Kepler-98 b completes one full revolution every 1.542 Earth days at a semi-major axis of 0.02614 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 184.5 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 1592 K (+1319°C / +2406°F) and receiving 1,107.39 S⊕ (~1,507,156 W/m²), Kepler-98 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Kepler-98 is classified as a stellar host with an effective photospheric temperature of 5,539 K, a radius of 1.11 R☉, a mass of 0.99 M☉, an estimated bolometric luminosity of 1.041 L☉. Stellar evolution modeling indicates an estimated stellar age of 2.79 Gyr and a metallicity of [Fe/H] = 0.18 dex (metal-rich relative to the Sun). From Earth, Kepler-98 shines at apparent V-band magnitude 12.996 (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-98 |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | 5,539 K |
| Stellar Radius | 1.1100 R☉ |
| Stellar Mass | 0.9900 M☉ |
| Bolometric Luminosity | 1.041 L☉ |
| Metallicity [Fe/H] | 0.180 dex |
| Stellar Age | 2.790 Gyr |
| Apparent Magnitude | V: 12.996 · G: 12.869 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.026140 AU |
| Orbital Period | 1.542 days |
| Mean Orbital Velocity | 184.5 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 86.4700° |
| Mean Bulk Density | 2.48 g/cm³ (14.9 km/s vesc) |
| Insolation Flux | 1107.3890 S⊕ (~1,507,156 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1142.600 LY (350.315 pc) |