b Cen AB b
Astrophysical Synthesis & Habitability Characterization
b Cen AB b is a confirmed gas giant exoplanet orbiting the star b Cen A, located approximately 319.9 light-years (98.09 parsecs) from the Solar System. First announced in 2021 by Paranal Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 12.4 Earth radii (1.11 Jupiter radii) and has a measured mass of 3464.33 Earth masses (10.9 Jupiter masses). Combining its mass and radius yields a mean bulk density of 10.02 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 22.53 g⊕ (220.94 m/s²), and an escape velocity of 187 km/s.
In its orbital architecture around b Cen A, b Cen AB b completes one full revolution every 1790000 Earth days (4900.75Julian years) at a semi-major axis of 556 AU (a wide outer-system orbit beyond Jupiter's 5.20 AU distance in our Solar System). Its mean orbital velocity is approximately 3.4 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.4, swinging from 333.6 AU at periapsis out to 778.4 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 12.400 R⊕, b Cen AB 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 b Cen A is classified as a massive B-type star of spectral type B2.5 V with a mass of 5.5 M☉. Stellar evolution modeling indicates an estimated stellar age of 0.015 Gyr. From Earth, b Cen A shines at apparent V-band magnitude 4.01 (visible to the unaided human eye under dark skies) in the Southern 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: Paranal Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | b Cen A |
| Spectral Type | B2.5 V |
| Effective Temp (Teff) | — |
| Stellar Radius | — |
| Stellar Mass | 5.5000 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 0.015 Gyr |
| Apparent Magnitude | V: 4.010 · G: 4.011 |
| System Architecture | 2 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 556.000000 AU |
| Orbital Period | 1790000 days |
| Mean Orbital Velocity | 3.4 km/s |
| Orbital Eccentricity (e) | 0.40000 |
| Orbital Inclination (i) | 143.0000° |
| Mean Bulk Density | 10.02 g/cm³ (187 km/s vesc) |
| Insolation Flux | — |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 319.900 LY (98.094 pc) |