Wendelstein-2 b
Astrophysical Synthesis & Habitability Characterization
Wendelstein-2 b is a confirmed gas giant exoplanet orbiting the star Wendelstein-2, located approximately 1844.5 light-years (565.54 parsecs) from the Solar System. First announced in 2020 by Haleakala Observatory using the Transit detection technique (producing an estimated primary transit depth of 3.2574% across the stellar disk), this world measures 12.993 Earth radii (1.16 Jupiter radii) and has a measured mass of 232.334 Earth masses (0.73 Jupiter masses). Combining its mass and radius yields a mean bulk density of 0.58 g/cm³ (a low bulk density dominated by an extended hydrogen-helium gaseous envelope), a surface gravity of 1.38 g⊕ (13.53 m/s²), and an escape velocity of 47.3 km/s.
In its orbital architecture around Wendelstein-2, Wendelstein-2 b completes one full revolution every 1.752 Earth days at a semi-major axis of 0.0234 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 145.3 km/s (compared to Earth's 29.8 km/s). Its moderate orbital eccentricity of e = 0.057 carries the world between 0.0221 AU at periapsis and 0.0247 AU at apoapsis, driving measurable seasonal insolation cycles.
⚠️ Thermal Regime (Irradiated / Hot Zone): At an equilibrium temperature of 2470 K (+2197°C / +3987°F) and receiving 282.31 S⊕ (~384,224 W/m²), Wendelstein-2 b orbits interior to the runaway greenhouse boundary where surface liquid water cannot persist.
The host star Wendelstein-2 is classified as an orange K-type star of spectral type K6 V with an effective photospheric temperature of 4,591 K, a radius of 0.66 R☉, a mass of 0.73 M☉, an estimated bolometric luminosity of 0.174 L☉. From Earth, Wendelstein-2 shines at apparent V-band magnitude 16.186 (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: Haleakala Observatory · Catalogue Source: NASA Exoplanet Archive (IPAC / Caltech).
☀️ Host Star Telemetry
| Host Star Name | Wendelstein-2 |
| Spectral Type | K6 V |
| Effective Temp (Teff) | 4,591 K |
| Stellar Radius | 0.6600 R☉ |
| Stellar Mass | 0.7300 M☉ |
| Bolometric Luminosity | 0.174 L☉ |
| Metallicity [Fe/H] | — |
| Stellar Age | — |
| Apparent Magnitude | V: 16.186 · G: 15.936 |
| System Architecture | 1 Star, 1 Planet |
🪐 Orbital & Physical Dynamics
| Semi-Major Axis (a) | 0.023400 AU |
| Orbital Period | 1.752 days |
| Mean Orbital Velocity | 145.3 km/s |
| Orbital Eccentricity (e) | 0.05700 |
| Orbital Inclination (i) | 87.8700° |
| Mean Bulk Density | 0.58 g/cm³ (47.3 km/s vesc) |
| Insolation Flux | 282.3101 S⊕ (~384,224 W/m²) |
| Habitable Zone Status | Exterior / Non-HZ |
| Celestial Distance | 1844.500 LY (565.541 pc) |