K2-18 is 124 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this M2.5 V star; the first was found in 2015 by transit (K2).
Fly there in 3DK2-18 c goes round its star every 8.96 days, 10 times as often as Mercury goes round the Sun.
| Spectral type | M2.5 V |
| Surface temperature | 3,457 K |
| Mass | 0.359 solar masses |
| Radius | 0.411 solar radii |
| Luminosity | 0.0253 times the Sun |
| Apparent magnitude | 13.477 |
| Distance from the Sun | 124.0 light-years (38.0 parsecs) |
| Position (J2000) | RA 172.5601°, Dec 7.5878° |
| Constellation | Leo |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| K2-18 c disputed | 8.96 days | 0.0600 AU | 2.65 R⊕ estimated | 7.51 M⊕ minimum | Radial Velocity, 2017 |
| K2-18 b | 32.9 days | 0.143 AU | 2.37 R⊕ | 8.92 M⊕ | Transit, 2015 |
Values are the NASA Exoplanet Archive’s composite parameters. A radius marked estimated comes from a mass–radius relation; a mass marked minimum is M sin i. Planet sizes and colours in the 3D view are renderings: none of these worlds has been photographed as more than a point of light.
For a star of 3,457 K, 0.025 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 0.16 to 0.32 AU. None of its known planets orbits inside it. The zone says how much starlight arrives, not whether a planet has water or air. The edges follow Kopparapu et al. (2014), as the 3D view draws them.
The light you see left 124 years ago, around 1900.