BD+20 2457 is 5,022 light-years from the Sun. The NASA Exoplanet Archive lists 2 planets around this K2 II star; the first was found in 2009 by radial velocity (McDonald Observatory).
Fly there in 3DBD+20 2457 c takes 622.0 days to go round its star once.
| Spectral type | K2 II |
| Surface temperature | 4,137 K |
| Mass | 2.8 solar masses |
| Radius | 49 solar radii |
| Luminosity | 1479 times the Sun |
| Apparent magnitude | 9.743 |
| Distance from the Sun | 5021.9 light-years (1539.7 parsecs) |
| Position (J2000) | RA 154.1868°, Dec 19.8913° |
| Constellation | Leo |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| BD+20 2457 b | 379.6 days | 1.450 AU | 12.1 R⊕ estimated | 6807.6 M⊕ minimum | Radial Velocity, 2009 |
| BD+20 2457 c | 622.0 days | 2.010 AU | 12.4 R⊕ estimated | 3963.2 M⊕ minimum | Radial Velocity, 2009 |
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 4,137 K, 1,479 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 39.38 to 74.11 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 5,022 years ago, around 3000 BC.