AST 111 Lecture Notes - Lecture 2: Dailymotion, Sept, Declination
Document Summary
Naked eye astronomy had an important place in civilizations of the past. They were not alone in the study of the sky. Eighty-eight constellations dead where memorialized in the stone around the groupings. Asterisms are less formal groups of stars. The big dipper is not a constellation: the living people who built it lived in a circle of (recently) living wood, while the. Constellations are the names of recognizable patterns in the sky as well as the sky. The night sky changes during the night and from one night to the next. Diurnal motion (daily motion) is caused by the rotation of the earth around its 24 hour axis. Annual (yearly) motion is caused by the revolution of the earth around the sun. It is convineint to imagine that the stars are in a sphere. Appears to rotate from east to west because the earth is rotating from east to west.
