northern circumpolar constellations. what does circumpolar mean? to circle around the pole- or north...

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. • 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.

This is what I mean:

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

The Big Dipper shows the way to Polaris

But it is not a real constellation:

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.

The Little Dipper w/ Polaris

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’.

Draco the Dragon

The King and Queen

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.

These are the stars visible in the southern polar sky.