Luhman 16 b
Astrophysical Synthesis & Habitability Characterization
Luhman 16 b is a confirmed gas giant exoplanet orbiting the star Luhman 16 A. First announced in 2017 by Multiple Observatories using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 11.9 Earth radii (1.06 Jupiter radii) and has a measured mass of 9344.155 Earth masses (29.4 Jupiter masses). Combining its mass and radius yields a mean bulk density of 30.57 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 65.99 g⊕ (647.14 m/s²), and an escape velocity of 313.5 km/s.
In its orbital architecture around Luhman 16 A, Luhman 16 b completes one full revolution every 9697 Earth days (26.55Julian years) at a semi-major axis of 3.52 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 3.9 km/s (compared to Earth's 29.8 km/s). The planet follows a highly eccentric trajectory (e = 0.344, swinging from 2.3091 AU at periapsis out to 4.7309 AU at apoapsis), pointing to past dynamical scattering or secular gravitational perturbations.
☁️ Atmospheric Regime (Volatile / Gas Envelope): With a radius of 11.900 R⊕, Luhman 16 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 Luhman 16 A is classified as a stellar host with a mass of 0.0338 M☉.
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: Multiple Observatories · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Luhman 16 A |
| Spectral Type | Unclassified |
| Effective Temp (Teff) | — |
| Stellar Radius | — |
| Stellar Mass | 0.0338 M☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | — |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 3.520000 AU |
| Orbital Period | 9697 days |
| Mean Orbital Velocity | 3.9 km/s |
| Orbital Eccentricity (e) | 0.34400 |
| Orbital Inclination (i) | 79.9200° |
| Mean Bulk Density | 30.57 g/cm³ (313.5 km/s vesc) |
| Insolation Flux | 0.0000 S⊕ |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | — |