AS101 Lecture Notes - Lecture 8: Tidal Locking, Retrograde And Prograde Motion, Antarctic Circle
Document Summary
Stars closer to the npc than the horizon are circumpolar they never get below the horizon. Close to the ncp means declination close enough to +90. For latitude 43n, that means between 47 and 90. They are close to the scp so they never get above the horizon. Their locations on the celestial sphere are exactly on the opposite side of the ce from the ones that are north circumpolar. The sun: think of the sun just like any other star. Suppose we"re at 45 n latitude, and lets think about where the sun is when it crosses the meridian. Our zenith is 45 north of the celestial equator, and the sun is. 23. 5 north, so the sun is 45-23. 5=21. 5 away from the zenith. 90-21. 5=68. 5 , so that is the suns altitude. Suppose we"re at 45 latitude, and lets think about where the sun is when it crosses the meridian.
