WD 1856+534 b
Astrophysical Synthesis & Habitability Characterization
WD 1856+534 b is a confirmed gas giant exoplanet orbiting the star WD 1856+534, located approximately 80.7 light-years (24.74 parsecs) from the Solar System. First announced in 2020 by Transiting Exoplanet Survey Satellite (TESS) using the Transit detection technique (producing an estimated primary transit depth of 5297.4355% across the stellar disk), this world measures 10.4 Earth radii (0.93 Jupiter radii) and has a measured mass of 4386.054 Earth masses (13.8 Jupiter masses). Combining its mass and radius yields a mean bulk density of 21.5 g/cm³ (an iron-enriched, high-compression rocky core), a surface gravity of 40.55 g⊕ (397.66 m/s²), and an escape velocity of 229.7 km/s.
In its orbital architecture around WD 1856+534, WD 1856+534 b completes one full revolution every 1.408 Earth days at a semi-major axis of 0.0204 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 157.6 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 (Cryogenic Zone): With an equilibrium temperature of 163 K (-110°C / -166°F) and an incident flux of 0.18 S⊕ (~246 W/m²), surface water and volatile species on WD 1856+534 b would remain locked in cryogenic ice phases unless warmed by subsurface tidal or radiogenic heating.
The host star WD 1856+534 is classified as a catalogued stellar host of spectral type DC with an effective photospheric temperature of 4,710 K, a radius of 0.0131 R☉, a mass of 0.518 M☉, an estimated bolometric luminosity of 0.00008 L☉. Stellar evolution modeling indicates an estimated stellar age of 7.93 Gyr. From Earth, WD 1856+534 shines at apparent V-band magnitude 17.244 (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: Transiting Exoplanet Survey Satellite (TESS) · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | WD 1856+534 |
| Spectral Type | DC |
| Effective Temp (Teff) | 4,710 K |
| Stellar Radius | 0.0131 R☉ |
| Stellar Mass | 0.5180 M☉ |
| Bolometric Luminosity | 0.00008 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | 7.930 Gyr |
| Apparent Magnitude | V: 17.244 · G: 16.958 |
| System Architecture | 3 Stars, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.020400 AU |
| Orbital Period | 1.408 days |
| Mean Orbital Velocity | 157.6 km/s |
| Orbital Eccentricity (e) | 0.00000 |
| Orbital Inclination (i) | 88.7780° |
| Mean Bulk Density | 21.5 g/cm³ (229.7 km/s vesc) |
| Insolation Flux | 0.1810 S⊕ (~246 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 80.700 LY (24.736 pc) |