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Northern Circumpolar Constellations. What does circumpolar mean?. to circle around the pole- or North Star. daily trace circles around the north celestial pole, without setting or dipping below the horizon. move in a counterclockwise direction.
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What does circumpolar mean? • to circle around the pole- or North Star. • daily trace circles around the north celestial pole, without setting or dipping below the horizon. • move in a counterclockwise direction. • On any given night, the constellation is visible during a portion of the circle; the rest is traced out when the constellation is hidden in the daylight sky.
Circumpolar Constellations: • Ursa Major, the Big Bear (includes the Big Dipper) • Ursa Minor, the Little Bear • Cassiopeia, the Queen of Ethiopia • Cepheus, the King of Ethiopia • Draco the Dragon
What is it? An ASTERISM • The Big Dipper and Little Dipper are part of two other official constellations • The Great Bear and Little Bear respectively. • They are a familiar, but unofficial grouping of stars.
Why is Polaris so important? • it stays relatively fixed in the heavens while all of the other stars move in circular arcs throughout the night. • In the past, it has been called ‘the ship star’, ‘the leading star’, ‘star of the sea’ and the ‘steering star’ • Native Americans called it the ‘nail of the sky’.
Does Precession effect the Pole Star? YES!! • The Earth is like a spinning top.
This wobble changes the spot that the Earth’s axis points to in the Northern sky.