The big cat of spring has help chasing Orion and his dogs 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 Marshall southwestern sky. There’s the big guy himself with 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 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 side of Orion’s gang of winter shiners are his hunting dogs; the constellations Canis Major and Canis Minor. Canis Major actually looks like a little 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 50 trillion miles away, and believe it or not that is chump change when it come to stellar distances.
Canis Minor, Orion’s little dog, is a joke of a constellation. All there is to it is basically two stars next to each other, a bright one and a dim one. The bright one is Procyon, 11.5 light- years away, the next brightest star you see to the upper left of Sirius. The dimmer 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, climbing higher and higher in the southeast evening in pursuit of the mighty hunter and the pooches of winter. Leo is one of the few constellations that really 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 behemoth 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 completely gone from the night sky.
This annual chase is reenacted every spring, and we can thank the Earth’s orbit around the sun for making this happen. As our home planet circles the sun, the nighttime side of the Earth faces different directions in space and different constellations. As this happens, we on Earth watch pretty much all of the stars shift westward from night to night. That’s why we have different sets of constellations from season to season.
If you’re a real night owl and you’re up around midnight, well after Leo has chased Orion and his pooches out the sky, you can watch the great planet Jupiter rise above the southeast horizon. You can’t miss it. It’s brighter than any other star in the sky at that time. Right now the biggest planet in our solar system is about 427 million miles away, but in early June the distance between our Earth and Jupiter will be reduced to less than 400 million miles, making Jupiter a tremendous telescope target … Stay tuned!
CELESTIAL HUGGING THIS WEEK: In the early morning all this week in the low southern sky, about 60 to 90 minutes before sunrise, the waning full moon will be passing the bright planets Jupiter and Saturn as well as the bright constellation Sagittarius the Archer. Sagittarius actually looks much more like a teapot!
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul. He is also the author of “Stars: a Month by Month Tour of the Constellations,” published by Adventure Publications and available at bookstores and at adventurepublications.net.