On 14 January your 0550 DR position is LAT 25°26.0'N, LONG 38°16.0'W. You observe an unidentified star bearing 212°T at an observed altitude (Ho) of 41°42.3'. The chronometer reads 08h 48m 51s, and is 01m 22s slow. What star did you observe?

Correct Answer: Option B — Gienah

Convert chronometer time to GMT, then determine GHA Aries and the star's SHA. Calculate LHA by combining GHA and longitude. By comparing the calculated LHA and Declination against the Nautical Almanac star index, Gienah is identified as the body matching the observed altitude and bearing.