AST101H1 Lecture Notes - Lecture 5: Ecliptic, Celestial Pole, Light Pollution

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Eryan Apsnler, Michael Reid

Document Summary

In cities, light pollution prevents one from being able to see more than a few dozen stars. From a remote location, one can see thousands of stars. To better understand the sky, most cultures have grouped stars into constellations. Such grouping implies that all stars in the constellation is related. Not actually the case; their location is coincidental. All the stars that form constellations are at entirely different locations; from a cosmic standpoint, they do not form patterns as we like to think. 88 western constellations completely cover the sky so that every part of the sky bears a name. Earth spins on its axis once every 24 hours; in addition to this rotation, it orbits the sun 365 times more slowly. Most bodies in space rotate and/or orbit in a counterclockwise direction (some exceptions exist) One can imagine that all of the stars are attached to a transparent celestial sphere".