Astronomy 1021 Chapter Notes - Chapter 2: Circumpolar Star, Celestial Equator, March Equinox

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Reynold Silber

Document Summary

Sky as seen from wherever you are standing. Imaginary half-circle from north horizon to south horizon. Locate an object by specifying its altitude and direction (azimuth) The angle an object appears to span in your field of view (ex: sun is 1/2 degrees) Angle between two objects in the sky. Average time it takes the sun to make one circuit through the sky. Time it takes any star to make one full circuit through the sky. Region in the sky with well-defined borders. An illusion, as we lack depth perception when we look into space. Ancient greeks mistook this illusion as a great celestial sphere that surrounds earth. North celestial pole: point directly over north pole. South celestial pole: point directly over south pole. Celestial equator: projection of earth"s equator into space, complete circle in celestial sphere. Ecliptic: path of the sun, crosses celestial sphere at 23 1/2 degrees because of earth"s tilt.