On 23 September your 1836 DR position is LAT 25°18'S, LONG 162°23'E. You observe an unidentified star bearing 000°T at an observed altitude (Ho) of 26°18'. The chronometer reads 07h 34m 12s, and is 01m 54s slow. What star did you observe?

Correct Answer: Option D — Vega

Calculate the Greenwich Hour Angle (GHA) of Aries and the Local Hour Angle (LHA) of the star using the DR longitude. By comparing the observed altitude and azimuth against the Nautical Almanac’s tabulated values for stars at that specific LHA and latitude, Vega is identified as the only body matching these coordinates.