On 28 September in DR position LAT 27°16.7'S, LONG 113°27.2'W, you observe an amplitude of the Sun. The Sun's center is on the celestial horizon and bears 273°psc. The chronometer reads 01h 17m 26s and is 01m 49s slow. Variation in the area is 6°W. What is the deviation of the standard magnetic compass?

Question

On 28 September in DR position LAT 27&deg;16.7'S, LONG 113&deg;27.2'W, you observe an amplitude of the Sun. The Sun's center is on the celestial horizon and bears 273&deg;psc. The chronometer reads 01h 17m 26s and is 01m 49s slow. Variation in the area is 6&deg;W. What is the deviation of the standard magnetic compass?

Accepted Answer

Option B: 0.4&deg;E. Calculate the Sun's declination and the observer's latitude to determine the amplitude angle. Apply the formula sin(Amp) = sin(Dec) / cos(Lat). Convert the true amplitude to a true bearing, then compare it to the compass bearing. Adjusting for variation of 6°W yields a deviation of 0.4°E.