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MCQAdvancedCelestial Coordinates & Time
USAAAO — 2025 First Round
Question 20
Just before dawn of the summer solstice, Christopher the sailor begins sailing due West from 50° N, 5° W. His watch is set to UTC. On seeing his 91st sunrise at sea, his watch reads 8:44am. What is his longitude? (The equation of time, in the convention solar time minus mean time, is −3 minutes on the summer solstice and 8 minutes on the autumnal equinox) [Watch reading updated from the original exam’s 3:00am, which placed the ship east of Greenwich, contradicting the westward voyage.]
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Source
USAAAO 2025 First Round, Question 20. Question text, choices, and answer were transcribed from the official USAAAO exam and solutions PDFs.