K2-170 is 1,281 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this 5,748 K star; the first was found in 2018 by transit (K2).
Fly there in 3DK2-170 b goes round its star every 7.58 days, 12 times as often as Mercury goes round the Sun.
Where the archive gives only a period or only an orbit size, the other is worked out from Kepler’s third law with the star’s mass.
| Surface temperature | 5,748 K |
| Mass | 0.963657 solar masses |
| Radius | 0.981614 solar radii |
| Luminosity | 1.18 times the Sun |
| Apparent magnitude | 12.668 |
| Distance from the Sun | 1281.4 light-years (392.9 parsecs) |
| Position (J2000) | RA 335.4507°, Dec -14.5934° |
| Constellation | Aquarius |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| K2-170 b | 7.58 days | 0.0746 AU from Kepler’s law | 1.4182 R⊕ | 2.6 M⊕ estimated | Transit, 2018 |
| K2-170 c | 12.4 days | 0.104 AU from Kepler’s law | 1.8018 R⊕ | 3.9 M⊕ estimated | Transit, 2018 |
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 5,748 K, 1.2 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 1.03 to 1.83 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 1,281 years ago, around AD 740.