الجدي vs Vega
| الخاصية | الجدي | Vega |
|---|---|---|
| التسمية | 1Alp UMi | 3Alp Lyr |
| الكوكبة | N/A | Lyra |
| النوع الطيفي | Class F — F-type (Yellow-White) | Class A — A-type (White) |
| القدر الظاهري | +1.97 | +0.03 |
| القدر المطلق | -3,64 | 0,60 |
| المسافة | 433 ly | 25.0 ly |
| الكتلة | N/A | N/A |
| نصف القطر | N/A | N/A |
| درجة الحرارة | N/A | N/A |
| السطوع | N/A | N/A |
الاختلافات الرئيسية
- ◆ Polaris is an F-type Cepheid variable supergiant; Vega is a stable A-type main-sequence star.
- ◆ Polaris is 431 light-years away; Vega is much closer at 25 light-years.
- ◆ Polaris sits near the north celestial pole and has guided navigators for centuries; Vega was the pole star ~14,000 years ago.
- ◆ Vega served as the original zero-magnitude reference for the photometric system.
- ◆ Polaris pulsates in brightness; Vega has a debris disk suggesting a forming planetary system.