AS101 Lecture Notes - Lecture 4: The Constellations
Document Summary
The sun and moon are unevenly pulling on the slight (43km) bulge around the earth"s equator. Demo/analogy: top spinning at an angle like the earth spins on a tilt. What happened to the axis of rotation: axis of rotation is the handle, handle stayed at the same angle but traced out a circle. This very slowly changes the position of the ncp, and all the other coordinates. The constellations are arbitrary patterns of stars invented by (mostly) ancient cultures: the great bear, the caribou (inuit, the big dipper. The sky is divided into parcels that each contain the constellation and other stars or objects in the same part of the sky. The stars in a constellation are not at the same distance from the earth, just in the same direction. All the patterns made by the stars will change as the sun (and other stars) will slowly orbit the centre of the milky way.
