Dubhe vs Merak
| Eigenschaft | Dubhe | Merak |
|---|---|---|
| Bezeichnung | 50Alp UMa | 48Bet UMa |
| Sternbild | Ursa Major | Ursa Major |
| Spektralklasse | Class F — F-type (Yellow-White) | Class A — A-type (White) |
| Scheinbare Helligkeit | +1.81 | +2.34 |
| Absolute Helligkeit | -1,07 | 0,40 |
| Entfernung | 123 ly | 79.7 ly |
| Masse | N/A | N/A |
| Radius | N/A | N/A |
| Temperatur | N/A | N/A |
| Leuchtkraft | N/A | N/A |
Wesentliche Unterschiede
- ◆ Both form the famous 'pointer stars' of the Big Dipper — drawing a line through them leads to Polaris.
- ◆ Dubhe is a K-type giant at ~123 light-years; Merak is an A-type main-sequence star at ~80 light-years.
- ◆ Merak is a member of the Ursa Major Moving Group and hosts a debris disk; Dubhe is not a member and moves separately.
- ◆ Dubhe has a radius of ~30 R☉, having evolved off the main sequence; Merak remains on the main sequence at ~3 R☉.
- ◆ Despite their pairing in navigation lore, the two stars are at quite different distances and unrelated physically.