51 Eri is 97.1 light-years from the Sun. The NASA Exoplanet Archive lists 1 planet around this F0 IV star; the first was found in 2015 by imaging (Gemini Observatory).
Fly there in 3D51 Eri b was photographed directly: it is one of the few exoplanets seen as its own point of light rather than inferred from its star.
51 Eri is one of 3 stars in its system: 51 Eri C drawn from the Washington Double Star Catalog; the position of one more star is not catalogued, so it is not drawn.
| Spectral type | F0 IV |
| Surface temperature | 7,422 K |
| Mass | 1.75 solar masses |
| Radius | 1.45 solar radii |
| Luminosity | 5.72 times the Sun |
| Apparent magnitude | 5.21149 |
| Age | about 0.0232 billion years |
| Distance from the Sun | 97.1 light-years (29.8 parsecs) |
| Position (J2000) | RA 69.4007°, Dec -2.4738° |
| Constellation | Eridanus |
51 Eri C is a M0.5 star of magnitude 10.59, judged a true companion. In 2003 it was 66.7″ from 51 Eri, at position angle 163° (Washington Double Star Catalog, 04376-0228 WAL 32 AC): 1,985 AU on the sky at this distance. The true distance can only be larger.
| Planet | Year | Orbit | Radius | Mass | Found |
|---|---|---|---|---|---|
| 51 Eri b | 24.9 years | 10.400 AU | — | 3464.3 M⊕ | Imaging, 2015 |
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 7,422 K, 5.7 times as bright as the Sun, the habitable zone, where starlight could keep water liquid on a rocky surface, runs from about 2.08 to 3.59 AU (approximate: the star lies just outside the range the formula was fitted to). 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 97 years ago, within living memory.