dipper@utastro.UUCP (Debbie Byrd) (08/23/84)
Altair is the least conspicuous star in the Summer Triangle -- but it's still pretty noticeable. We'll be talking about Altair -- in just a moment. August 16: The Star in the Eagle High in the evening sky now, there's a star you might be able to recognize and name -- even without a star chart. It's Altair, in the constellation Aquila the eagle. Altair isn't the brightest star around, but its fairly bright -- and noticeable for its two fainter companions, which flank it on either side. This straight-line trio of stars can now be found high in the southeast each evening. Altair lies at the edge of the Milky Way, the hazy starlit trail now visible in a dark-enough sky. Its constellation, Aquila, is supposed to represent an eagle belonging to Jupiter, the king of gods. In starlore, this eagle once swooped to Earth to kidnap a boy called Ganymede, whom Jupiter wanted as a member of his court. Today, Ganymede is also the name for the largest moon of the planet Jupiter. So Aquila is the constellation of the eagle -- and Altair is its brightest star. Its chief claim to fame is that it's one of the three stars that make up the simple star pattern we call the Summer Triangle. The other Summer Triangle stars are Vega, in the constellation Lyra, and Deneb, in the constellation Cygnus. But there's one other thing to distinguish Altair -- its rapid spin. Altair is some two to three times larger than our sun, which takes about 26 days to turn on its axis. And yet like many other stars, Altair spins much faster than the sun. It completes a single spin in less than a day on Earth! Script by Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin