Betelgeuse vs Sirio
The two are not neighbours in any sense: 8.60 light-years against 498. Sirio is an A-type star in Canis Major, while Betelgeuse is an M-type star in Orion. Apparent magnitudes of −1.44 and +0.45 place Sirio some 5.7 times brighter in the sky than Betelgeuse. Absolute magnitudes of −5.47 for Betelgeuse and +1.45 for Sirio put a factor near 586 between their true outputs.
Property comparison
| Property | Betelgeuse | Sirio |
|---|---|---|
| Designación | 58Alp Ori | 9Alp CMa |
| Constelación | Orion | Canis Major |
| Clase Espectral | Class M — M-type (Red) | Class A — A-type (White) |
| Magnitud Aparente | +0.45 | -1.44 |
| Magnitud Absoluta | -5.47 | 1.45 |
| Distancia | 498 ly | 8.6 ly |
| Masa | N/A | N/A |
| Radio | N/A | N/A |
| Temperatura | N/A | N/A |
| Luminosidad | N/A | N/A |
Full data for each star: Betelgeuse · Sirio
Key differences
Key Differences
- ◆ Sirius is an A-type main-sequence star; Betelgeuse is an M-type red supergiant nearing the end of its life.
- ◆ Betelgeuse has a radius of ~887 R☉ — over 500 times larger than Sirius at 1.71 R☉.
- ◆ Sirius is only 8.6 light-years away; Betelgeuse is about 700 light-years distant.
- ◆ Betelgeuse is luminosity-dominant at ~126,000 L☉ versus Sirius at 25.4 L☉.
- ◆ Sirius is the brightest star in the night sky; Betelgeuse is a famous supernova candidate.