On 22 May your 0437 ZT DR position is LAT 25°18.5' N, LONG 51°18.0' W. You observe an unidentified star bearing 097°T at an observed altitude (Ho) of 48°20.0'. The chronometer reads 07h 40m 40s and is 03m 24s fast. What star did you observe?

Correct Answer: Option B — Markab

Calculate GMT by applying chronometer error to the reading. Determine LHA of Aries and the star's GHA. Using Pub. 229, compare the observed altitude and azimuth against the computed values for potential stars. Markab aligns with the coordinates, confirming it as the observed body for the given DR.