ASTA01H3 Lecture Notes - Lecture 1: Orbital Period, Apsis, Tidal Locking
Document Summary
Local meridian: the circle that passes through north, south and zenith. An object"s altitude (above horizon) and direction (along horizon) specify its location in your local sky. Altitude: the elevation of a star above the local horizon measured in degrees. A star rises when it comes above the horizon and sets when it goes below the horizon. The larger the declination, the farther from the point of west the star sets. If the declination of a star is larger than 90 - latitude, then that star never sets and always remain above the horizon. Circumpolar constellations are those which always stay above the horizon and never set. The declination of a circumpolar star is equal or larger than = 90 - . From higher latitudes you see more circumpolar constellations since (90 - latitude) is a smaller number and thus more stars qualify as circumpolar.
