Alnilam
star · Orion · 1.7ᵐ
The middle star of Orion’s Belt and the farthest of the three, at about 2,000 light years. A blue supergiant hundreds of thousands of times more luminous than the Sun.
Notable facts
The light you see today left Alnilam around the year 49.
About 53 times brighter than the faintest star visible to the naked eye.
In brief
Which constellation is Alnilam in?
Alnilam lies in Orion.
Is Alnilam visible to the naked eye?
1.7ᵐ — visible to the naked eye (under dark skies).
When is the best time to observe Alnilam?
Best observed in December.
Data
- RA / Dec (J2000)
- 5h 36m · −1° 12′
- Type
- star
- Constellation
- Orion
- How to observe
- 1.7ᵐ — visible to the naked eye (under dark skies)
- Spectral class
- B0Ia — blue-white star
- Absolute magnitude
- -7.2ᵐ
- Luminosity (visual)
- ≈66,000 × the Sun
- Distance
- ~1,977 light years
- Designation
- HIP 26311
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° | 29° | 92° |
| +55° | 34° | 92° |
| +45° | 44° | 92° |
| +30° | 59° | 91° |
| 0° | 89° | 91° |
| −35° | 56° | 91° |
Geometric altitude at upper culmination, atmospheric refraction not included. Positive latitudes are in the northern hemisphere.
Culmination time by month
| Month | Culmination |
|---|---|
| January | 21:51 |
| February | 19:43 |
| March | 17:58 |
| April | 16:05 |
| May | 14:10 |
| June | 12:04 |
| July | 10:00 |
| August | 07:59 |
| September | 06:06 |
| October | 04:18 |
| November | 02:17 |
| December | 00:08 |
Upper culmination in local solar time — no time-zone or daylight-saving correction applied.