HAT-P-20 is 232 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this K3 star; the first was found in 2010 by transit (HATNet).
Fly there in 3DHAT-P-20 b goes round its star every 2.88 days, 31 times as often as Mercury goes round the Sun.
| Spectral type | K3 |
| Surface temperature | 4,595 K |
| Mass | 0.756 solar masses |
| Radius | 0.694 solar radii |
| Luminosity | 0.1901 times the Sun |
| Apparent magnitude | 11.231 |
| Age | about 6.7 billion years |
| Distance from the Sun | 231.7 light-years (71.0 parsecs) |
| Position (J2000) | RA 111.9164°, Dec 24.3361° |
| Constellation | Gemini |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| HAT-P-20 b | 2.88 days | 0.0361 AU | 9.718 R⊕ | 2302.9 M⊕ | Transit, 2010 |
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 4,595 K, 0.19 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 0.44 to 0.81 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 232 years ago, around 1790.