Celestial Navigation · Hour Angle — SHA and Stars
The GHA of a star is found from:
- AGHA Aries + the star's sidereal hour angle (SHA)✓ Correct
- BGHA of the sun − SHA
- CThe star's declination ÷ 15
- DLHA + assumed longitude
Explanation
Stars are tabulated by SHA (referenced to the First Point of Aries) plus declination, which change slowly. GHA star = GHA Aries (from the daily pages for the GMT) + SHA star. LHA star is then GHA star ± longitude.
Authority: Nautical Almanac, daily pages
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