Achernar
star · Eridanus · 0.5ᵐ
Its extremely rapid rotation makes it the most oblate of all known bright stars.
Notable facts
The light you see today left Achernar around the year 1887.
About 166 times brighter than the faintest star visible to the naked eye.
In brief
Which constellation is Achernar in?
Achernar lies in Eridanus.
Is Achernar visible to the naked eye?
0.5ᵐ — visible to the naked eye (under dark skies).
When is the best time to observe Achernar?
Best observed in October.
Data
- RA / Dec (J2000)
- 1h 38m · −57° 14′
- Type
- star
- Constellation
- Eridanus
- How to observe
- 0.5ᵐ — visible to the naked eye (under dark skies)
- Spectral class
- B3Vp — blue-white star
- Absolute magnitude
- -2.7ᵐ
- Luminosity
- ≈1,038 × the Sun
- Distance
- ~139 light years
- Designation
- HIP 7588
Observing tip
Stars stay points at any magnification: aim your telescope for colour, brightness and companions, not detail.
Altitude above the horizon by latitude
| Latitude | Maximum altitude | Rise azimuth |
|---|---|---|
| +60° | never rises | — |
| +55° | never rises | — |
| +45° | never rises | — |
| +30° | 3° | 166° |
| 0° | 33° | 147° |
| −35° | 68° · never sets | — |
Geometric altitude at upper culmination, atmospheric refraction not included. Positive latitudes are in the northern hemisphere.
Culmination time by month
| Month | Culmination |
|---|---|
| January | 17:52 |
| February | 15:45 |
| March | 14:00 |
| April | 12:06 |
| May | 10:12 |
| June | 08:06 |
| July | 06:02 |
| August | 04:01 |
| September | 02:08 |
| October | 00:19 |
| November | 22:18 |
| December | 20:10 |
Upper culmination in local solar time — no time-zone or daylight-saving correction applied.