Star · B3V
Achernar
Achernar is a main-sequence star of spectral type B3V in the constellation Eridanus, 139.4 light-years from the Sun.
| Other names | α Eri · HIP 7588 |
|---|---|
| Constellation | Eridanus |
| Distance | 139.4 light-years (42.8 pc) |
| Apparent magnitude | magnitude 0.45 |
| Absolute magnitude | magnitude −2.70 |
| Spectral type | B3V |
| Surface temperature | 12,650 K |
| Luminosity | 2,190 L☉ |
| Radius | 9.75 R☉ |
| Mass | 8.18 M☉ (estimated) |
| Right ascension (J2000) | 1h 37m 42.8s |
| Declination (J2000) | −57° 14′ 12″ |
| Space velocity (relative to the Sun) | 21.1 km/s |
In the sky
Visible to the naked eye under a dark sky (apparent magnitude 0.45). Visible from the whole Southern Hemisphere and north to latitude 33° N. South of latitude 33° S it never sets. It stands highest at midnight in October, the best time to observe it.
Through a telescope from Earth
Light's journey
The light you see tonight set out around the year 1887. At the speed of Voyager 1, the fastest craft leaving the Solar System (16.9 km per second), the trip would take 2.5 million years.
The Sun seen from there
From a planet around Achernar, the Sun would look like a star of magnitude 7.98, in the direction where our sky has the constellation Ursa Major. It would be invisible to the naked eye.
Neighbours
Its nearest neighbours in the catalogue (within 20 light-years):
- HIP 7290 4.99 light-years
- HIP 7387 8.10 light-years
- HIP 7990 8.32 light-years
- HIP 6485 9.55 light-years
- HIP 8035 12.3 light-years
- HIP 7699 13.8 light-years
- HIP 7241 14.3 light-years
- HIP 8987 14.3 light-years
Position, brightness and colour from the HYG / AT-HYG catalogue; temperature, luminosity, radius and mass are approximate values computed from these observations.