At 0520 zone time on 17 March, while taking stars for a morning fix, you observe an unidentified star bearing 050°T, at an observed altitude (Ho) of 45°00.0'. Your DR position at the time of the sight is LAT 27°23.0'N, LONG 39°42.0' W. The chronometer time of the sight is 08h 22m 15s, and the chronometer error is 01m 45s fast. Your vessel is steaming on a course of 300°T at a speed of 18 knots. What star did you observe?
Official USCG Answer & Rule Citation
Correct Answer: Option D — Deneb
Convert chronometer time to GMT, then determine the LHA of Aries and the star's sidereal hour angle. Calculate the star's computed azimuth and altitude using the DR position. Comparing these coordinates against the observed bearing of 050°T and altitude of 45°00.0' confirms the star is Deneb.
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