Kepler-251 is 3,016 light-years from the Sun. The NASA Exoplanet Archive lists 4 planets around this 5,526 K star; the first was found in 2014 by transit (Kepler).
Fly there in 3DKepler-251 b goes round its star every 4.79 days, 18 times as often as Mercury goes round the Sun.
| Surface temperature | 5,526 K |
| Mass | 0.891 solar masses |
| Radius | 0.89 solar radii |
| Luminosity | 0.673 times the Sun |
| Apparent magnitude | 15.541 |
| Age | about 2 billion years |
| Distance from the Sun | 3015.7 light-years (924.6 parsecs) |
| Position (J2000) | RA 296.5662°, Dec 44.1058° |
| Constellation | Cygnus |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| Kepler-251 b | 4.79 days | 0.0530 AU | 1.33 R⊕ | 2.33 M⊕ estimated | Transit, 2014 |
| Kepler-251 c | 16.5 days | 0.122 AU | 2.77 R⊕ | 8.1 M⊕ estimated | Transit, 2014 |
| Kepler-251 d | 30.1 days | 0.182 AU | 2.77 R⊕ | 8.1 M⊕ estimated | Transit, 2014 |
| Kepler-251 e | 99.6 days | 0.404 AU | 2.77 R⊕ | 8.1 M⊕ estimated | Transit, 2014 |
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 5,526 K, 0.67 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 0.79 to 1.41 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 3,016 years ago, around 1000 BC.