'If you've seen one star, you've seen 'em all.”
I can't tell you how many times I have heard these words before stargazing sessions – but never afterward. That's because anyone who has taken the time to look carefully at the heavens knows that each star has a unique personality.
One of the most visible qualities that distinguishes a star is its color. Colors indicate a star's temperature. Those that appear white are hotter than those that are orange or red. And bluish stars are hottest of all.
Trying to see these hues, however, can be a challenge, since the human eye's color receptors don't respond well under low-light conditions. You know this to be true if you've ever looked around a darkened movie theater; shapes and shades of gray are pretty easy to spot, but colors are virtually nonexistent.
Yes, star colors are subtle, and anyone with even the slightest color blindness might miss them altogether – especially since colorful stars are often widely separated in the sky. But there is a place where a hot star and a cool star lie close together and, when viewed with a small telescope, always elicit oohs and ahs.
Astronomers call it Beta Cygni, but we also know it by its proper name: Albireo. Albireo lies near the center of the Summer Triangle – formed by the bright stars Deneb, Vega and Altair – high in the eastern sky after dark this week. It forms the head of Cygnus, the swan, also known as the Northern Cross.
Albireo is the fifth brightest star in Cygnus and appears single to the eye, but aim a small telescope in its direction and you will easily be able to resolve its light into that of two separate stars. One of the components of this binary system is a yellow star (about 7,700 degrees Fahrenheit) and the other is a bluish star (19,500 degrees).
The stars of Albireo are located some 380 light-years from us. They orbit a common center of gravity, but don't expect to see any movement while you're watching. One orbital cycle takes about 75 centuries to complete.
This summer make sure you aim a small telescope toward the head of the celestial swan. And then check out some of the other bright stars overhead. You may just be surprised to learn that if you've seen one star, you've not seen them all.
© Creators Syndicate Inc.
