K2-32 b
K2-32 b is a Neptune-like planet orbiting K2-32 in the constellation Ophiuchus. It lies about 514 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is K2-32 b?
K2-32 b has a radius of 5.30 times that of Earth. Its mass is 15.0 times that of Earth, giving it a density of 0.55 g/cm³ — closer to gas planets like Jupiter (1.33 g/cm³).
Is K2-32 b in the Habitable Zone?
K2-32 b orbits inside the inner edge of the habitable zone of K2-32. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of K2-32: 0.553–1.323 AU (conservative: 0.700–1.255 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
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Temperature on K2-32 b
The equilibrium temperature of K2-32 b is about 837 K (564 °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 K2-32 b — one full orbit around K2-32 — lasts 8.99 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.080 AU — closer to its star than Mercury is to the Sun. Its orbit is nearly circular (eccentricity 0.030).
How Was K2-32 b Discovered?
K2-32 b was discovered in 2016 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 K2-32 b?
K2-32 b is 514.3 light-years (157.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1512. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 9,051,680 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. K2-32 b scores 0.16, ranking #4,157 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-32
K2-32 b belongs to a system of 2 stars; it orbits K2-32.
K2-32
- Surface temperature
- 5,271 K (Sun: 5,772 K)
- Mass
- 0.83 M☉
- Radius
- 0.86 R☉
The K2-32 Planetary System
K2-32 b is one of 4 known planets in the K2-32 system. Its siblings:
K2-32 b — Complete Data
| Radius | 5.299 Earth radii (0.473 Jupiter radii) |
|---|---|
| Mass | 15.00 Earth masses (0.047 Jupiter masses) |
| Density | 0.55 g/cm³ (Earth: 5.51) |
| Orbital period | 8.99 days |
| Orbital distance | 0.080 AU |
| Eccentricity | 0.030 |
| Equilibrium temperature | 837 K (564 °C) |
| Earth Similarity Index | 0.16 |
| Distance from Earth | 514.3 light-years (157.7 parsecs) |
| Constellation | Ophiuchus |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2021-05-17. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-32 b
Is K2-32 b habitable?
No — K2-32 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is K2-32 b?
K2-32 b is about 514 light-years from Earth in the constellation Ophiuchus. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 9,051,680 years to get there.
How big is K2-32 b compared to Earth?
K2-32 b has 5.30 times the radius of Earth and about 15.0 times its mass.
How long is a year on K2-32 b?
One orbit around K2-32 takes 9.0 Earth days — short enough that 41 of its years would fit into one Earth year.
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