On 22 March your 0519 DR position is LAT 27°20.6'N, LONG 69°25.6'W. You observe an unidentified star bearing 115°T at an observed altitude (Ho) of 54°52.8'. The chronometer reads 10h 16m 47s, and is 02m 15s slow. What star did you observe?
Official USCG Answer & Rule Citation
Correct Answer: Option A — Altair
Convert chronometer time to GMT and determine GHA Aries. Calculate LHA for the DR position. Using the Sight Reduction Tables (Pub. 229), compare the computed altitude and azimuth with the observed values. The intersection of these parameters confirms the star is Altair, consistent with the observed bearing.
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