Gemini is one of the brightest of the 66 constellations that we see through the course of the year around here, and it’s easy to find in my favorite part of the sky, “Orion and his gang.” Just look for the famous constellation Orion the Hunter in the southwest sky as soon as it’s dark enough in the evening. You can’t miss it. It’s the one that looks like a tilted giant hourglass with three very distinct stars in a perfect row that make Orion’s belt. There’s a bright reddish star to the upper left of Orion’s belt called Betelgeuse that marks the armpit of the mighty celestial hunter.
Just above and a little to the left of Orion’s armpit star is where you’ll find the constellation Gemini with its brightest “twin” stars, Castor and Pollux.
Castor and Pollux mark the heads of the mythological twins, Castor and Pollux. Unless you’re looking from an area of heavy city lighting, you should see two faint parallel lines of stars to the lower right of the stars Castor and Pollux. Those are the bodies of the twins that remind me of stickmen that kids like to draw. The feet of Castor and Pollux are not that far away from Orion’s armpit star, Betelgeuse.
Slowly scan Gemini with binoculars or a telescope and you’ll see some nice star clusters, groups of young stars that were born out of the same giant gas cloud. The brightest stars in Gemini, Castor and Pollux have quite a story all by themselves. Pollux is a giant star, more than nine million miles in diameter. That’s 11 times the diameter of our sun. It’s also 30 times more luminous than our sun, and sports a surface temperature of more than 7,500 degrees Fahrenheit, which is a little cooler than that of our home star.
Gazing at the star Castor proves that heavenly looks can be really deceiving. A moderate telescope reveals that Castor appears to be a beautiful double star, but a larger telescope reveals that one of those stars is actually a collection of six stars all revolving around each other in an intricate cosmic ballet. Can you imagine living on a planet going around one of those stars? You’d have six sunrises and six sunsets every day.
According to Greek mythology Castor and Pollux were the twin sons of Leda, the queen of Sparta. The twins, though, have two different fathers. Castor was the son of Leda’s husband, King Tyndarus, but Pollux’s dad is Zeus, the king of the gods. How can I put this in a family newspaper? Let’s just say nine months before the twins were born Queen Leda had quite a night. Greek mythology is full of this kind of behavior.
Anyway, the result was that Castor was mortal and Pollux was half god because of his father. The twins grew up together and had the finest of everything, including a great education. They were the best of friends, as well as brothers. They hung out together all the time, even after they grew up. Castor became one of the finest horsemen in the land and Pollux became a championship boxer.
One of the stories goes that Castor and Pollux fell in love with two beautiful sisters, who already were promised to two other suitors. Castor and Pollux challenged the pair and killed them in a fight, but Castor suffered a mortal wound, and Pollux lost his brother and best friend.
Castor went off to the underworld and Pollux missed him like crazy. He longed for the day that he could join his brother again, but that was impossible since Pollux was immortal. He begged his father Zeus to do something, so he could see his best friend again. Finally Zeus allowed Pollux to spend half of each day with Castor in the underworld and the other half of each day in this world. It wasn’t like the old days but it was better than nothing. In the end, Zeus placed them both in the heavens as a symbol of brotherly love.
The love these twins had for each other is celebrated in the skies every night, and over the years, the constellation Gemini became a good luck charm to sailors and travelers throughout the world.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and author of the new book “Washington Starwatch,” available at bookstores and on his Web site, www.lynchandthestars.com.