Wedded Bliss?

The only married couple in the sky are moving higher and higher as summer progresses. They are Cepheus and Cassiopeia, king and queen of Ethiopia.

They are both easy to find: Cassiopeia is a "W" that is as far from the pole to the east as the Big Dipper is to the west; Cepheus is a little "house" halfway between the pole and Cassiopeia. The peak of the house is midway between Polaris and Cassiopeia; the rest of the house extends to the south.

Were they a happy couple? Their closeness in the sky suggests that. But wait. The star that marks the peak of the roof of Cepheus is his foot, and his body is the rest of the house, to the south. Cassiopeia, however, sits on her throne with her head to the north. The two are sitting head to foot! Maybe their marriage was less than perfect after all.

Well, the story goes that Cassiopeia was so vain, and so boasted of her beauty that she enraged the king of the sea, Poseidon. In his anger, Poseidon sent a sea monster to ravage her land. When her husband inquired of the oracles what was to be done, he was given the fateful news that their daughter Andromeda had to be sacrificed. (She was saved later, but that's another story, and, anyhow, Cassiopeia and Cepheus didn't know that then.) A frightful wedge to drive a married couple apart!

But Cepheus wasn't only the bearer of ill-tidings. He was first one of the Argonauts, the heroes who sailed across the seas in search of the golden fleece. That Cepheus captured the heart of Cassiopeia. The near-tragedy came later.

To modern observers, Cassiopeia is a treasure trove of magnificent star clusters. Just panning through Cassiopeia with a modest pair of binoculars offers exquisite views.

But it is to Cepheus that one of the most important stars in the sky belongs: ;delta Cepheus, a star essential to knowing the distances to the galaxies. It flickers, and how fast stars like it flicker tells us how bright they really are. If they appear dim, itıs only because theyıre very far away. This was the key needed to tell us how distant galaxies really are - and how big the universe is.

(07/20/05)