K2-389 is 845 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this G3 star; the first was found in 2022 by transit (K2).
Fly there in 3DK2-389 b goes round its star every 8.58 days, 10 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.
| Spectral type | G3 |
| Surface temperature | 5,773 K |
| Mass | 0.99 solar masses |
| Radius | 1.094 solar radii |
| Luminosity | 1.278 times the Sun |
| Apparent magnitude | 11.827 |
| Distance from the Sun | 845.4 light-years (259.2 parsecs) |
| Position (J2000) | RA 355.6304°, Dec -9.7136° |
| Constellation | Aquarius |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| K2-389 b | 8.58 days | 0.0818 AU from Kepler’s law | 2.33 R⊕ | 6.04 M⊕ estimated | Transit, 2022 |
| K2-389 c | 20.9 days | 0.148 AU from Kepler’s law | 2.04 R⊕ | 4.82 M⊕ estimated | Transit, 2022 |
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 5,773 K, 1.3 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 1.07 to 1.90 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 845 years ago, around 1180.