AST101H1 Chapter Notes -International Astronomical Union, Celestial Equator, Northern Hemisphere

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

Document Summary

On a clear, moonless nights far from city lights, more than 2000 stars may be visible to your naked eye, along with the milky way. Constellation: a region of the sky with well-defined borders; the familiar patterns of stars merely help us locate the constellations. The names and borders of the 88 official constellations were chosen in 1928 by members of the. The stars in a particular constellation appear to lie close to one another but may be quite far apart in reality, because they lie at very different distances from earth. Illusion occurs because we lack depth perception when we look into space, a consequence of the fact that the stars are so far away. The ancient greeks mistook this illusion for reality, imagining the stars and constellation to lie on a great celestial sphere that surrounds the earth. The north celestial pole is the point directly over earth"s north pole.