Alnilam vs Zeta Orionis
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 Zeta Orionis as an O-type star in Orion. The two are near-identical in apparent brightness, Alnilam at magnitude +1.69 and Zeta Orionis at +1.74. Only 736 light-years separate the Sun from Zeta Orionis; Alnilam sits 2.7 times further out at 1,977.
Property comparison
| Property | Alnilam | Zeta Orionis |
|---|---|---|
| Ký Hiệu | 46Eps Ori | 50Zet Ori |
| Chòm Sao | Orion | Orion |
| Phân Loại Quang Phổ | Class B — B-type (Blue-White) | Class O — O-type (Blue) |
| Cấp Sao Biểu Kiến | +1.69 | +1.74 |
| Cấp Sao Tuyệt Đối | -7.22 | -5.03 |
| Khoảng Cách | 1,977 ly | 736 ly |
| Khối Lượng | N/A | N/A |
| Bán Kính | N/A | N/A |
| Nhiệt Độ | N/A | N/A |
| Độ Sáng | N/A | N/A |
Full data for each star: Alnilam · Zeta Orionis
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.