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?

Question

At 0520 zone time on 17 March, while taking stars for a morning fix, you observe an unidentified star bearing 050&deg;T, at an observed altitude (Ho) of 45&deg;00.0'. Your DR position at the time of the sight is LAT 27&deg;23.0'N, LONG 39&deg;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&deg;T at a speed of 18 knots. What star did you observe?

Accepted Answer

Option C: Deneb. Convert chronometer time to GMT, then determine the GHA and Declination of the star. Using the LHA and DR latitude, calculate the computed altitude (Hc) and azimuth. Comparing these values against the observed data identifies the star as Deneb, consistent with its position in the Nautical Almanac.