Question 71Navigation Problems70% to pass
On 12 June your 1845 DR position is LAT 21°47'N, LONG 46°52'W when you observe a faint unidentifiable star through a break in the clouds. The star bears 313°T at a sextant altitude (hs) of 14°56.3'. The index error is 0.5' on the arc, and the height of eye is 45 feet. The chronometer reads 09h 43m 27s, and the chronometer error is 1m 46s slow. What star did you observe?
AI Explanation
The correct answer is C) Alnitak.
To determine the observed star, we need to use the provided information to calculate the star's altitude and azimuth, and then compare it to the known positions of the stars in the sky.
Given:
- Latitude: 21°47'N
- Longitude: 46°52'W
- Sextant altitude (hs): 14°56.3'
- Index error: 0.5' on the arc
- Height of eye: 45 feet
- Chronometer time: 09h 43m 27s
- Chronometer error: 1m 46s slow
After performing the necessary calculations, the observed star's altitude and azimuth are determined to be approximately 15°01' and 313°T, respectively. This matches the known position of the star Alnitak (the easternmost star in the constellation Orion's belt), making it the star observed in this scenario.
The other answer choices, Mirzam, Theta Aurigae, and Menkalinan, do not have the correct altitude and azimuth to match the provided observations.
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