K2-149 b
K2-149 b is a super-Earth orbiting the M1.0 V star K2-149 in the constellation Pisces. It lies about 403 light-years from Earth and was discovered in 2018 using the transit method.
How Big Is K2-149 b?
K2-149 b has a radius of 1.64 times that of Earth.
Is K2-149 b in the Habitable Zone?
K2-149 b orbits inside the inner edge of the habitable zone of K2-149. So close to its star, surface conditions are far too hot for liquid water.
Habitable zone of K2-149: 0.180–0.463 AU (conservative: 0.229–0.438 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 K2-149 b
K2-149 b receives 7.00 times the stellar energy that Earth gets from the Sun.
Orbit and Year Length
A year on K2-149 b — one full orbit around K2-149 — lasts 11.3 Earth days, shorter than Mercury's 88-day year. It orbits at an average distance of 0.083 AU — closer to its star than Mercury is to the Sun.
How Was K2-149 b Discovered?
K2-149 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 K2-149 b?
K2-149 b is 403.4 light-years (123.7 parsecs) from Earth. Light arriving here tonight left the planet around the year 1623. A probe traveling at the speed of Voyager 1 — about 17 km/s, the fastest outbound spacecraft ever launched — would need roughly 7,099,840 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. K2-149 b scores 0.44, ranking #356 of 5,568 planets with a known ESI. For reference, Mars scores about 0.70.
The Host Star: K2-149
K2-149
- Spectral type
- M1.0 V
- Surface temperature
- 3,745 K (Sun: 5,772 K)
- Mass
- 0.60 M☉
- Radius
- 0.57 R☉
- Luminosity
- 0.0490 L☉
Planetary System
K2-149 b is the only planet known to orbit K2-149 so far.
K2-149 b — Complete Data
| Radius | 1.640 Earth radii (0.146 Jupiter radii) |
|---|---|
| Orbital period | 11.33 days |
| Orbital distance | 0.083 AU |
| Stellar irradiation | 7.00× Earth |
| Earth Similarity Index | 0.44 |
| Distance from Earth | 403.4 light-years (123.7 parsecs) |
| Constellation | Pisces |
| Discovery method | Transit |
| Discovery facility | K2 |
| Discovery year | 2018 |
Data: NASA Exoplanet Archive, last updated 2018-02-01. Earth Similarity Index: PHL @ UPR Arecibo.
Frequently Asked Questions About K2-149 b
Is K2-149 b habitable?
No — K2-149 b orbits too close to its star and is too hot for liquid water to exist on its surface.
How far away is K2-149 b?
K2-149 b is about 403 light-years from Earth in the constellation Pisces. A spacecraft traveling as fast as Voyager 1 (about 17 km/s) would need roughly 7,099,840 years to get there.
How big is K2-149 b compared to Earth?
K2-149 b has 1.64 times the radius of Earth.
How long is a year on K2-149 b?
One orbit around K2-149 takes 11.3 Earth days — short enough that 32 of its years would fit into one Earth year.