On 24 July your 1912 zone time DR position is LAT 24°28.0' N, LONG 73°46.5' W. Considering their magnitude, azimuth, and altitude, which group includes the three stars best suited for a fix at star time?
• Star selection for a three‑star fix (good spread in azimuth, suitable altitudes, and bright stars of adequate magnitude) • Observer’s DR position and latitude (24° N) and approximate local time/date (24 July, evening star time in western Atlantic) • Desirability of stars with wide azimuth separation and moderate altitudes (not too low, not near the zenith)
• From 24° N in late July at evening/star time, which group looks like it would give you stars spread around the horizon instead of all in the same quadrant? • Which choice gives stars that are all reasonably bright navigation stars and likely to be above your horizon at that date, latitude, and local time? • For each group, imagine approximate directions (N/S/E/W) and heights of those stars; which set avoids stars that are too low, too high, or bunched in azimuth?
• Check that the chosen group has good azimuth spread (ideally 60°–120° between stars, not all close together). • Verify that each star in the group would have a comfortable altitude (about 15°–75°) from LAT 24° N, not grazing the horizon or overhead. • Confirm that each candidate is a well‑known, bright navigation star that is likely to be available near evening nautical twilight on 24 July at about 74° W.
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