Jimmy Westlake: Cassiopeia's Chair

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One of the first star patterns to catch your eye in the early fall sky is a distinctive group of five bright stars high in the northeast forming the shape of the letter "W," rotated counterclockwise on its side. Meet Cassiopeia, the Queen. The five stars of the W pattern actually form the outline of the Queen's chair, hanging upside down in the sky. Why upside down?

Cassiopeia is being punished for her boastful, bragging ways. She had a bad habit of doting on her lovely daughter, Andromeda, and once went so far as to claim that Andromeda was more beautiful and fair than the Sea Nymphs. The Sea Nymphs were the pride and joy of Poseidon, the mythological god of the sea, and he didn't take too kindly to Cassiopeia's boasting. Poseidon punished Cassiopeia by placing her in the sky very close to the pole star so that, as she rotates around the pole, she would spend half of the year upside down, clinging to her throne for dear life. Let this be a lesson to all the vain and boastful people out there.

Cassiopeia occupies a spot in the sky diametrically opposed to the North Star from the Big Dipper, so, one or the other star pattern is visible any time of the night, any night of the year. From Colorado, Cassiopeia is a circumpolar constellation, meaning it never actually sets below the northern horizon but just barely skims above the mountaintops before rising high again.

The star Caph, at the top of the W, is the closest of Cassiopeia's five main stars at a distance of 54 light years, while the star marking the middle of the W is the most distant at 613 light years. This star, simply referred to as Gamma, is the brightest unnamed star in the northern hemisphere. Perhaps it was much fainter centuries ago when the Greeks and Arabs were giving the stars their colorful names. Gamma is known today to be an unpredictable variable star that occasionally increases dramatically in brightness. For example, in 1937, Gamma briefly brightened to rival the brightest stars in the sky, then dwindled to a very unimpressive third-magnitude star before rebounding to its present second-magnitude status.

While you are exploring the neighborhood of Cassiopeia, see if you can spot the famous Double Cluster in the star clouds of the Milky Way just below the Queen's Chair. Visible to the naked eye as a fuzzy patch of light, the Double Cluster reveals twin clusters containing dozens of twinkling stars when viewed through binoculars or a small telescope. It is one of the most beautiful and unique celestial objects visible from our planet.

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