Celestial Navigation · Polaris — Azimuth
Polaris is useful for a compass check at night because its azimuth is:
- AEqual to the observer's longitude
- BAlways due east
- CConstantly changing through 360° each hour
- DAlways very close to true north (000°/360°), within about a degree✓ Correct
Explanation
Because Polaris is so near the celestial pole, its true azimuth is always within roughly 1° of 000°T. The Almanac's Polaris azimuth table gives the exact value, allowing a gyro or magnetic compass check by comparing the observed bearing of Polaris with true north.
Authority: Nautical Almanac, Polaris Tables (azimuth)
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