kap CrB b
Astrophysical Synthesis & Habitability Characterization
kap CrB b is a confirmed gas giant exoplanet orbiting the star kap CrB, located approximately 98.1 light-years (30.07 parsecs) from the Solar System. First announced in 2007 by Lick Observatory using the Radial Velocity detection technique (measuring periodic Doppler reflex motion in the host star's spectrum), this world measures 13.3 Earth radii (1.19 Jupiter radii) and has a measured mass of 689.691 Earth masses (2.17 Jupiter masses). Combining its mass and radius yields a mean bulk density of 1.62 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 3.9 g⊕ (38.25 m/s²), and an escape velocity of 80.6 km/s.
In its orbital architecture around kap CrB, kap CrB b completes one full revolution every 1253.68 Earth days (3.43Julian years) at a semi-major axis of 2.5 AU (corresponding to the middle-system regime between Mars at 1.52 AU and Jupiter at 5.20 AU). Its mean orbital velocity is approximately 21.7 km/s (compared to Earth's 29.8 km/s). With a near-circular eccentricity of e = 0.04 (ranging from 2.4 AU at periapsis to 2.6 AU at apoapsis), the planet experiences minimal orbital distance variation.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 13.300 R⊕, kap CrB b exceeds the empirical ~1.8–2.2 R⊕ Fulton radius valley threshold, indicating a substantial hydrogen-helium or supercritical volatile envelope without a conventional solid terrestrial surface.
The host star kap CrB is classified as an orange K-type star of spectral type K0 III-IV with an effective photospheric temperature of 4,840 K, a radius of 4.68 R☉, a mass of 1.33 M☉, an estimated bolometric luminosity of 10.784 L☉. Stellar evolution modeling indicates an estimated stellar age of 3.42 Gyr and a metallicity of [Fe/H] = 0.09 dex (metal-rich relative to the Sun). From Earth, kap CrB shines at apparent V-band magnitude 4.797 (visible to the unaided human eye under dark skies) 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: Lick Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | kap CrB |
| Spectral Type | K0 III-IV |
| Effective Temp (Teff) | 4,840 K |
| Stellar Radius | 4.6800 R☉ |
| Stellar Mass | 1.3300 M☉ |
| Bolometric Luminosity | 10.784 L☉ |
| Metallicity [Fe/H] | 0.090 dex |
| Stellar Age | 3.420 Gyr |
| Apparent Magnitude | V: 4.797 · G: 4.524 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 2.500000 AU |
| Orbital Period | 1253.68 days |
| Mean Orbital Velocity | 21.7 km/s |
| Orbital Eccentricity (e) | 0.04000 |
| Orbital Inclination (i) | 60.0000° |
| Mean Bulk Density | 1.62 g/cm³ (80.6 km/s vesc) |
| Insolation Flux | 1.7376 S⊕ (~2,365 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 98.100 LY (30.065 pc) |