Algol vs Polaris
Intrinsic output is the great divide here. Polaris carries an absolute magnitude of −3.64 to −0.11 for Algol, near 26 times the true luminosity. Algol trails in apparent brightness at magnitude +2.09 against +1.97, leaving Polaris around 1.1 times the brighter target. Polaris is an F-type star, while Algol is a B-type star in Perseus. Polaris is the remoter of the pair at 433 light-years, roughly 4.8 times the 89.9 that separates us from Algol.
Property comparison
| Property | Algol | Polaris |
|---|---|---|
| Designation | 26Bet Per | 1Alp UMi |
| Constellation | Perseus | N/A |
| Spectral Class | Class B — B-type (Blue-White) | Class F — F-type (Yellow-White) |
| Apparent Magnitude | +2.09 | +1.97 |
| Absolute Magnitude | -0.11 | -3.64 |
| Distance | 89.9 ly | 433 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: Algol · Polaris
Key differences
Key Differences
- ◆ Both are variable stars, but of different physical types.
- ◆ Polaris is a Cepheid variable that pulsates in radius; Algol dims because a companion eclipses it.
- ◆ Polaris's pulsation amplitude has been decreasing over the past century.
- ◆ Algol varies every 2.87 days (eclipsing); Polaris has a period of about 3.97 days (pulsation).
- ◆ Polaris is near the north celestial pole and vital for navigation; Algol is in Perseus and known as the Demon Star.