On 2 October your 1845 DR position is LAT 28°09.2'S, LONG 167°48.1'E. You observe a faint star through a hole in the clouds at a sextant altitude (hs) of 25°19.4' bearing 273°T. The index error is 1.3' off the arc, and the height of eye is 42 feet. The chronometer reads 07h 46m 19s and is 0m 51s fast. What star did you observe?
Official USCG Answer & Rule Citation
Correct Answer: Option C — Beta Librae
Correct the sextant altitude for index error, dip, and refraction to find Ho. Determine the GHA and Declination for the corrected GMT. Using the azimuth and Ho, perform a reverse sight reduction to identify the body's coordinates, which match the values for Beta Librae.
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