Alnilam vs Alnitak
A 2.19-magnitude difference in absolute output separates them, −7.22 to −5.03. Catalogues list Alnilam as a B-type star in Orion and Alnitak as an O-type star in Orion. The two are near-identical in apparent brightness, Alnilam at magnitude +1.69 and Alnitak at +1.74. Only 736 light-years separate the Sun from Alnitak; Alnilam sits 2.7 times further out at 1,977.
Property comparison
| Property | Alnilam | Alnitak |
|---|---|---|
| Designation | 46Eps Ori | 50Zet Ori |
| Constellation | Orion | Orion |
| Spectral Class | Class B — B-type (Blue-White) | Class O — O-type (Blue) |
| Apparent Magnitude | +1.69 | +1.74 |
| Absolute Magnitude | -7.22 | -5.03 |
| Distance | 1,977 ly | 736 ly |
| Mass | N/A | N/A |
| Radius | N/A | N/A |
| Temperature | N/A | N/A |
| Luminosity | N/A | N/A |
Full data for each star: Alnilam · Alnitak
Key differences
Key Differences
- ◆ Alnilam (Epsilon Orionis) is the central star of Orion's Belt; Alnitak (Zeta Orionis) is the eastern star.
- ◆ Alnilam is an F supergiant class at ~27,500 K; Alnitak is an O-type at ~29,500 K.
- ◆ Alnilam has a mass of ~40 M☉ versus Alnitak's ~33 M☉.
- ◆ Alnitak is closer at ~1,260 light-years; Alnilam is ~2,000 light-years away.
- ◆ Both are expected to end their lives as supernovae within the next few million years.