🔍 Key Concepts

• Star selection for a three-star fix (magnitude/brightness, azimuth separation, and altitude limits) • Your DR position, course, and hemisphere (South latitude, East longitude, heading 213°T) and how that affects which stars are well placed • The idea of good azimuth spread (ideally 60°–120° apart) and moderate altitudes (about 20°–70° above the horizon)

💭 Think About

• From your DR position in 25°S, 7°E, which of the listed stars are likely to be high in the sky and which might be very low or even below the horizon? • Which option gives three stars that are well spread around the horizon in azimuth, rather than all clustered in one general direction? • Think about which named stars are in the same general region of the sky (e.g., both northern, both southern, or near the same right ascension) and whether that would make them poor as a group for a three-star fix.

✅ Before You Answer

• Check which stars are easily visible and bright (first magnitude or brighter). Eliminate any group with a notably weaker star if the others are strong. • Verify which stars are southern vs. northern so you don’t choose a group that would put most of them too low or below the horizon from 25°S. • Before choosing, picture the azimuth spread: avoid any group where the stars are likely to be in the same quadrant of the sky, instead of spaced widely around you.