The stories behind the constellations don’t always match the pictures we see in the sky. Consider Corvus, which rises in the southeast in mid-evening. In Greek mythology, it represented a naughty crow. The god Apollo sent the crow to fetch a cup of water. Instead, Corvus spent days gorging on fresh figs. He then grabbed a water snake and told Apollo that it had kept him from completing his task. Apollo knew the crow was lying, so he flung Corvus, the cup, and the snake into the sky.
To modern eyes, though, the crow’s brightest stars form the outline of a sail. Going clockwise from the sail’s highest point as it rises, the stars are Delta, Gamma, Epsilon, and Beta Corvi.
A couple of the stars are binaries, with two stars bound together by gravity. But the main stars in those systems, and the single stars in the other two, have a lot in common. They’re all bigger, heavier, and brighter than the Sun. And at least three of them are late in life. They’ve used up all or most of the original hydrogen fuel in their cores. That’s made the stars puff up, which has made them shine much brighter.
Astronomers aren’t sure about the fourth star. It might be in the same phase of life as the others. On the other hand, it might be quite young — just settling into life as a mature star.
Look for the sail — or the crow — in the southeast after about 9:30 or 10. It’s due south after midnight.
We’ll talk about the crow’s water cup tomorrow.
Script by Damond Benningfield