Dubhe vs Merak
| 特性 | Dubhe | Merak |
|---|---|---|
| 名称 | 50Alp UMa | 48Bet UMa |
| 星座 | Ursa Major | Ursa Major |
| スペクトル型 | Class F — F-type (Yellow-White) | Class A — A-type (White) |
| 見かけの等級 | +1.81 | +2.34 |
| 絶対等級 | -1.07 | 0.40 |
| 距離 | 123 ly | 79.7 ly |
| 質量 | N/A | N/A |
| 半径 | N/A | N/A |
| 温度 | N/A | N/A |
| 光度 | N/A | N/A |
主な違い
- ◆ 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.