Wolf 503 b
Wolf 503 b is a mini-Neptune orbiting the K3.5 V star Wolf 503 in the constellation Virgo. It lies about 145 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is Wolf 503 b?
Wolf 503 b has a radius of 2.04 times that of Earth. Its mass is 6.3 times that of Earth, giving it a density of 2.92 g/cm³ — between that of rocky and gaseous planets.
Is Wolf 503 b in the Habitable Zone?
Wolf 503 b orbits inside the inner edge of the habitable zone of Wolf 503. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of Wolf 503: 0.364–0.891 AU (conservative: 0.461–0.845 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on Wolf 503 b
The equilibrium temperature of Wolf 503 b is about 790 K (517 °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 Wolf 503 b — one full orbit around Wolf 503 — lasts 6.00 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.057 AU — closer to its star than Mercury is to the Sun. Its orbit is highly elliptical (eccentricity 0.41), swinging dramatically closer to and farther from its star.
How Was Wolf 503 b Discovered?
Wolf 503 b was discovered in 2018 using the transit method, with observations from K2.
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 Wolf 503 b?
Wolf 503 b is 145.2 light-years (44.5 parsecs) from Earth. Light arriving here tonight left the planet around the year 1881. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 2,555,520 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. Wolf 503 b scores 0.27, ranking #2,582 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: Wolf 503
Wolf 503
- Spectral type
- K3.5 V
- Surface temperature
- 4,716 K (Sun: 5,772 K)
- Mass
- 0.69 M☉
- Radius
- 0.69 R☉
- Luminosity
- 0.2110 L☉
- Age
- 11.0 billion years (Sun: 4.6)
Planetary System
Wolf 503 b is the only planet known to orbit Wolf 503 so far.
Wolf 503 b — Complete Data
| Radius | 2.043 Earth radii (0.182 Jupiter radii) |
|---|---|
| Mass | 6.26 Earth masses (0.020 Jupiter masses) |
| Density | 2.92 g/cm³ (Earth: 5.51) |
| Orbital period | 6.00 days |
| Orbital distance | 0.057 AU |
| Eccentricity | 0.410 |
| Equilibrium temperature | 790 K (517 °C) |
| Earth Similarity Index | 0.27 |
| Distance from Earth | 145.2 light-years (44.5 parsecs) |
| Constellation | Virgo |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2022-05-23. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About Wolf 503 b
Is Wolf 503 b habitable?
No — Wolf 503 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is Wolf 503 b?
Wolf 503 b is about 145 light-years from Earth in the constellation Virgo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 2,555,520 years to get there.
How big is Wolf 503 b compared to Earth?
Wolf 503 b has 2.04 times the radius of Earth and about 6.3 times its mass.
How long is a year on Wolf 503 b?
One orbit around Wolf 503 takes 6.0 Earth days — short enough that 61 of its years would fit into one Earth year.
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