WISEP J121756.91+162640.2 A b
Astrophysical Synthesis & Habitability Characterization
WISEP J121756.91+162640.2 A b is a confirmed gas giant exoplanet orbiting the star WISEP J121756.91+162640.2 A, located approximately 32.9 light-years (10.1 parsecs) from the Solar System. First announced in 2012 by W. M. Keck Observatory using the Imaging detection technique (resolved directly via high-contrast coronagraphic or interferometric imaging), this world measures 10.468 Earth radii (0.93 Jupiter radii) and has a measured mass of 6992 Earth masses (22 Jupiter masses). Combining its mass and radius yields a mean bulk density of 33.61 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 63.81 g⊕ (625.76 m/s²), and an escape velocity of 289.1 km/s.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 450 K (+177°C / +351°F), WISEP J121756.91+162640.2 A b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star WISEP J121756.91+162640.2 A is classified as a substellar T-dwarf of spectral type T8.5 with an effective photospheric temperature of 575 K, a radius of 0.091 R☉, a mass of 0.029 M☉, an estimated bolometric luminosity of 0.00000 L☉. Stellar evolution modeling indicates an estimated stellar age of 6 Gyr.
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: W. M. Keck Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WISEP J121756.91+162640.2 A |
| Spectral Type | T8.5 |
| Effective Temp (Teff) | 575 K |
| Stellar Radius | 0.0910 R☉ |
| Stellar Mass | 0.0290 M☉ |
| Bolometric Luminosity | 0.00000 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 6.000 Gyr |
| Apparent Magnitude | — |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 8.000000 AU |
| Orbital Period | — |
| Orbital Eccentricity (e) | Circular (0.00) |
| Orbital Inclination (i) | — |
| Mean Bulk Density | 33.61 g/cm³ (289.1 km/s vesc) |
| Insolation Flux | 0.0000 S⊕ |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 32.900 LY (10.100 pc) |