Wendelstein-2 b
Wendelstein-2 b is a hot Jupiter orbiting the K6 V star Wendelstein-2 in the constellation Sagitta. It lies about 1,845 light-years from Earth and was discovered in 2020 using the transit method.
How Big Is Wendelstein-2 b?
Wendelstein-2 b has a radius of 12.99 times that of Earth, or 1.16 times the radius of Jupiter. Its mass is 232 times that of Earth, giving it a density of 0.62 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is Wendelstein-2 b in the Habitable Zone?
Wendelstein-2 b orbits inside the inner edge of the habitable zone of Wendelstein-2. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Wendelstein-2: 0.332–0.817 AU (conservative: 0.421–0.775 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on Wendelstein-2 b
The equilibrium temperature of Wendelstein-2 b is about 2,470 K (2,197 °C) — hot enough to melt many metals. This estimate ignores any atmosphere, which could change surface temperatures dramatically — Earth's greenhouse effect adds about 33 °C.
Orbit and Year Length
A year on Wendelstein-2 b — one full orbit around Wendelstein-2 — lasts just 42.1 hours, shorter than Mercury's 88-day year. It orbits at an average distance of 0.023 AU — closer to its star than Mercury is to the Sun. Its orbit is mildly elliptical (eccentricity 0.06).
How Was Wendelstein-2 b Discovered?
Wendelstein-2 b was discovered in 2020 using the transit method, with observations from Haleakala Observatory.
The transit method watches a star for the tiny, regular dip in brightness that occurs when a planet crosses in front of it. The depth and timing of these dips reveal the planet's size and orbital period.
How Far Away Is Wendelstein-2 b?
Wendelstein-2 b is 1,844.5 light-years (565.5 parsecs) from Earth. Light arriving here tonight left the planet about 1,845 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 32,463,200 years to make the journey.
Earth Similarity Index
The Earth Similarity Index (ESI) scores how physically similar a planet is to Earth, from 0 to 1, based on radius, density, escape velocity and surface temperature. Wendelstein-2 b scores 0.07, ranking #4,869 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Wendelstein-2
Wendelstein-2
- Spectral type
- K6 V
- Surface temperature
- 4,591 K (Sun: 5,772 K)
- Mass
- 0.73 M☉
- Radius
- 0.66 R☉
Planetary System
Wendelstein-2 b is the only planet known to orbit Wendelstein-2 so far.
Wendelstein-2 b — Complete Data
| Radius | 12.993 Earth radii (1.159 Jupiter radii) |
|---|---|
| Mass | 232.33 Earth masses (0.731 Jupiter masses) |
| Density | 0.62 g/cm³ (Earth: 5.51) |
| Orbital period | 1.75 days |
| Orbital distance | 0.023 AU |
| Eccentricity | 0.057 |
| Equilibrium temperature | 2,470 K (2,197 °C) |
| Earth Similarity Index | 0.07 |
| Distance from Earth | 1,844.5 light-years (565.5 parsecs) |
| Constellation | Sagitta |
| Discovery method | Transit |
| Discovery facility | Haleakala Observatory |
| Discovery year | 2020 |
Data: NASA Exoplanet Archive, last updated 2020-07-02. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Wendelstein-2 b
Is Wendelstein-2 b habitable?
No — Wendelstein-2 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Wendelstein-2 b?
Wendelstein-2 b is about 1,845 light-years from Earth in the constellation Sagitta. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 32,463,200 years to get there.
How big is Wendelstein-2 b compared to Earth?
Wendelstein-2 b has 12.99 times the radius of Earth and about 232 times its mass.
How long is a year on Wendelstein-2 b?
One orbit around Wendelstein-2 takes 1.8 Earth days — short enough that 208 of its years would fit into one Earth year.
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