Alnilam vs Rigel
Rigel takes the naked-eye ranking at magnitude +0.18 to +1.69, worth about 4.0 times the light of Alnilam. Only 863 light-years separate the Sun from Rigel; Alnilam sits 2.3 times further out at 1,977. Alnilam is a B-type star in Orion; Rigel is a B-type star in Orion. Intrinsically the balance shifts: Alnilam carries an absolute magnitude of −7.22 against −6.93 for Rigel, making it about 1.3 times more luminous once distance is removed from the comparison.
Property comparison
| Property | Alnilam | Rigel |
|---|---|---|
| Designation | 46Eps Ori | 19Bet Ori |
| Constellation | Orion | Orion |
| Spectral Class | Class B — B-type (Blue-White) | Class B — B-type (Blue-White) |
| Apparent Magnitude | +1.69 | +0.18 |
| Absolute Magnitude | -7.22 | -6.93 |
| Distance | 1,977 ly | 863 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 · Rigel
Key differences
Key Differences
- ◆ Both are massive, highly luminous stars visible in Orion.
- ◆ Alnilam is the middle star of Orion's Belt — both are blue supergiants, though Alnilam is hotter at ~27,500 K versus Rigel's ~12,100 K.
- ◆ Alnilam is about 2,000 light-years distant; Rigel is closer at ~860 light-years.
- ◆ Alnilam has a mass of ~40 M☉, nearly double Rigel's ~21 M☉.
- ◆ Rigel is visible at the foot of Orion; Alnilam is the central jewel of Orion's Belt.