HD 209458 is 158 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this G0 V star; the first was found in 1999 by radial velocity (W. M. Keck Observatory).
Fly there in 3DHD 209458 b goes round its star every 3.52 days, 25 times as often as Mercury goes round the Sun.
| Spectral type | G0 V |
| Surface temperature | 6,091 K |
| Mass | 1.23 solar masses |
| Radius | 1.19 solar radii |
| Luminosity | 1.702 times the Sun |
| Apparent magnitude | 7.65 |
| Age | about 3.1 billion years |
| Distance from the Sun | 157.5 light-years (48.3 parsecs) |
| Position (J2000) | RA 330.7950°, Dec 18.8842° |
| Constellation | Pegasus |
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| HD 209458 b | 3.52 days | 0.0471 AU | 15.581 R⊕ | 232.02 M⊕ | Radial Velocity, 1999 |
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 6,091 K, 1.7 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 1.22 to 2.13 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 158 years ago, around 1870.