NATS 1740 Lecture Notes - Lecture 1: Celestial Sphere, International Astronomical Union

• School: York University
• Department: Natural Science
• Course: NATS 1740
• Professor: Amy Shaw

Document Summary

Most describe as patterns seen in night sky -astronomers define more presicely. Defined by astronomers as region in sky with well-defined borders. Names and borders of official constellations 1928 members of international. Stars in specific constellation apeear to lie close to one another but maybe far apart. This is due to the lack of depth preception, as stars are very far away. Ancient greeks thought celestial sphere was real and stars lay on it. Celestial sphere is useful for mapping the sky. Celestial equator:projection of earth"s equator into space making a complete circle around the celestial sphere. Ecliptic:path sun follows as it appears to circle celestial sphere once every year. Sun corsses equator at 23. 5 degrees angle b/c of earth"s tilt. Milky way: -shaped like a thin pancake with buldge in middle. Local sky: -sky seen from where you are standing.