Star · K1V
21 Eri
21 Eri is a main-sequence star of spectral type K1V in the constellation Eridanus, 112.9 light-years from the Sun.
| Other names | HIP 17027 |
|---|---|
| Constellation | Eridanus |
| Distance | 112.9 light-years (34.6 pc) |
| Apparent magnitude | magnitude 5.97 |
| Absolute magnitude | magnitude 3.27 |
| Spectral type | K1V |
| Surface temperature | 4,940 K |
| Luminosity | 5.93 L☉ |
| Radius | 3.32 R☉ |
| Mass | 1.56 M☉ (estimated) |
| Right ascension (J2000) | 3h 39m 01.1s |
| Declination (J2000) | −5° 37′ 34″ |
| Space velocity (relative to the Sun) | 53.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 5.97). Visible from the whole Southern Hemisphere and north to latitude 84° N. It stands highest at midnight in November, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1913. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.0 million years.
The Sun seen from there
From a planet around 21 Eri, the Sun would look like a star of magnitude 7.53, in the direction where our sky has the constellation Serpens. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 17165 6.80 light-years
- GJ 2030 12.7 light-years
- GJ 2030B 12.7 light-years
- SDSS J034408.91+011124.9 13.9 light-years
- WISEA J034409.71+013641.5 14.6 light-years
- Zibal 14.7 light-years
- SDSSp J032817.38+003257.2 15.3 light-years
- HIP 17888 16.1 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.