NATS 1740 Lecture Notes - Lecture 3: Celestial Pole, Celestial Equator, Tropical Year

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Tatiana Paulin

Document Summary

A region of the sky; 88 official constellations cover the celestial sphere. Familiar patterns of stars merely help us locate the constellations. Recognizing the pattern of just 20 or so constellations is enough to make the sky seem as familiar as your own neighbourhood. The stars in a particular constellation appear to lie close to one another but might be quite far apart in reality, because they may lie at very different distances from earth. North celestial pole: is the point directly over earth"s north pole. South celestial pole: is the point directly over the south pole. Celestial equator: which is a projection of earth"s equator into space, makes a complete circle around the celestial sphere. Ecliptic: is the path the sun follows as it appears to circle around the celestial sphere once each year. It crosses the celestial equator 23/5 angle, because that is the tilt of earth"s axis.