Great lion of spring is sweeping Orion out of the sky
Now that we’re well into spring and winter is history, at least astronomically, big changes are going on with our evening constellations.
Even though it’s spring, Orion and the rest of the winter constellations are still shining brightly in the Butler southwestern sky. Orion’s calling card is the three bright stars in a row that make up the hermit hunter’s belt. Orion’s brightest star is Rigel, marking Orion’s left knee, and Betelgeuse is at the other corner, marking Orion’s armpit. Betelgeuse is an Arabic name that roughly translates in English to “armpit of the great one.” Astronomically, Betelgeuse is a very significant star. It’s a super red giant star that at times bulges out to nearly a billion miles in diameter.
On the southern and eastern sides of Orion’s gang of winter shiners are his hunting dogs: the constellations Canis Major and Canis Minor.
Canis Major kind of looks like a dog with the very bright star Sirius marking the big dog’s snout. Sirius is the brightest star in the night sky. It’s so bright because it’s relatively close to Earth, at least as far as stars go. Sirius is a little over eight and a half light-years or about fifty trillion miles away. Believe it or not, that is chump change when it comes to stellar distances.
Canis Minor, Orion’s little dog, is a joke of a constellation. All there is to it is two stars next to each other, a bright one and a dim one. The bright one is Procyon, 11.5 light-years away. It’s the next brightest star you see to the upper left of Sirius. The fainter star to the upper right of Procyon is Gomeisa, and when you put them together you have Canis Minor. At my astronomy programs and parties, I refer to it as Orion’s little wiener dog!
Orion and his winter dogs are not long for our evening sky because one big kitty cat is chasing them.
The best constellation of the spring skies, Leo the Lion, is on the prowl, high in the early evening southern heavens in pursuit of the mighty hunter and the canines of winter. Leo is one of the few constellations that resembles what it’s supposed to be. The right side looks just like a backward question mark. It’s not hard to imagine that as the profile of the chest and head of a mighty lion. To the lower left of the backward question mark are three stars that form a distinct triangle that allegedly outlines the tail and hindquarters of Leo.
According to Greek mythology, Leo was king of all of the beasts. Not only was Leo a huge lion, but his hide was so tough that not even the sharpest sword at full thrust could pierce it! The mighty hunter Orion claimed he wasn’t afraid of Leo and boasted he could take on the big beast, but Orion was fearful that Leo would make mincemeat out of his faithful companions. That’s Orion’s story and he’s sticking to it! Rather than fight this fierce feline, Orion and his doggies make a night-to-night retreat toward the western horizon. By late May, the great winter hunter and his hounds are entirely gone from the night sky.
This annual chase occurs every spring thanks to the Earth’s orbit around the sun. As Earth circles the sun, the nighttime side of our planet faces different directions in space, and we on Earth watch the stars shift westward from night to night. That’s why we have different sets of constellations from season to season.
Despite Orion’s declaration of his great bravery, he’s a big scaredy-cat with Leo the Lion!
Celestial Happening this week: All the bright planets are on parade in the low southeastern early twilight sky. They’re nearly in straight line a little above the horizon. They’re the brightest star-like objects in that part of the sky.
Venus is by far the very brightest with Jupiter a little to the left of Venus. To the right of Venus is the Mars and Saturn. Mars has a distinct reddish hue. It’s worth waking up early for!
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Mike Lynch is an amateur astronomer and retired broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is the author of "Stars: a Month by Month Tour of the Constellations," published by Adventure Publications and available at bookstores and adventurepublications.net. Contact him at mikewlynch@comcast.net.
