🔍 Key Concepts

• Star selection for a twilight fix: you want stars that are well spread in azimuth (ideally 60°–120° apart) and at good altitudes (roughly 15°–75° above the horizon). • Observer’s position and sky area: your DR latitude (25° N) and local hour angle / GHA will affect which stars are high enough and not too close to the horizon or zenith. • Star magnitude and identification: brighter stars (lower magnitude numbers) are usually preferred for quick, accurate sights at twilight.

💭 Think About

• First think about your DR latitude 25° N: which of the listed stars are likely to be very far north, very far south, or near your zenith, and how does that affect their usefulness for a fix? • Consider the azimuth spread: if you draw rough bearings from your DR position to each candidate star, which choice gives you the widest, most even spread around the horizon? • At morning twilight, which of these stars are likely to be too low or not yet visible, versus comfortably above the horizon in the eastern and western parts of the sky?

✅ Before You Answer

• Check which stars in each choice give you good azimuth separation (avoid stars that are all in the same general quadrant of the sky). • Verify that each chosen star would have a reasonable altitude at that date and DR latitude—not grazing the horizon and not directly overhead. • Confirm that all stars in the group are bright, navigational stars commonly used in sight reduction (consult the star table for magnitude and declination).