K2-46 b
K2-46 b is a mini-Neptune orbiting K2-46 in the constellation Leo. It lies about 1,465 light-years from Earth and was discovered in 2016 using the transit method.
How Big Is K2-46 b?
K2-46 b has a radius of 2.05 times that of Earth.
Is K2-46 b in the Habitable Zone?
K2-46 b orbits inside the inner edge of the habitable zone of K2-46. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of K2-46: 1.102–2.569 AU (conservative: 1.396–2.436 AU), per Kopparapu et al. (2014). Earth orbits the Sun at 1 AU.
See the full interactive habitable-zone view in the Exoplanet Explorer app ›
Temperature on K2-46 b
K2-46 b receives 119 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on K2-46 b — one full orbit around K2-46 — lasts 19.2 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.138 AU — closer to its star than Mercury is to the Sun.
How Was K2-46 b Discovered?
K2-46 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 K2-46 b?
K2-46 b is 1,465.2 light-years (449.2 parsecs) from Earth. Light arriving here tonight left the planet about 1,465 years ago. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 25,787,520 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. K2-46 b scores 0.26, ranking #2,813 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-46
K2-46
- Surface temperature
- 6,256 K (Sun: 5,772 K)
- Mass
- 0.96 M☉
- Radius
- 1.29 R☉
Planetary System
K2-46 b is the only planet known to orbit K2-46 so far.
K2-46 b — Complete Data
| Radius | 2.050 Earth radii (0.183 Jupiter radii) |
|---|---|
| Orbital period | 19.15 days |
| Orbital distance | 0.138 AU |
| Stellar irradiation | 119.00× Earth |
| Earth Similarity Index | 0.26 |
| Distance from Earth | 1,465.2 light-years (449.2 parsecs) |
| Constellation | Leo |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2016 |
Data: NASA Exoplanet Archive, last updated 2016-07-14. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-46 b
Is K2-46 b habitable?
No — K2-46 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is K2-46 b?
K2-46 b is about 1,465 light-years from Earth in the constellation Leo. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 25,787,520 years to get there.
How big is K2-46 b compared to Earth?
K2-46 b has 2.05 times the radius of Earth.
How long is a year on K2-46 b?
One orbit around K2-46 takes 19.2 Earth days — short enough that 19 of its years would fit into one Earth year.