On Astronomy — Orion: My favorite constellation
The word constellation derives from Latin, a “set of stars” and Orion from Greek, “the hunter.” Some constellations are so obscure that they require imagination to see them. Orion is an exception. This beautiful constellation heralds in winter as it rises in the east after sunset.
Each night it rises higher and higher as it adorns the eastern skies all Winter. Orion easily invokes an image of a great hunter, holding a club over his right shoulder and a slain lion in his outstretched left hand. To me, he appears to be drawing an arrow back in his bow. In March, Orion hangs high in the southern sky. Following behind him, to the east, is his faithful dog, the constellation Canis Major, the dog that features the brightest star in the night sky, Sirius. By May, Orion is setting at sunset.
Orion’s belt is an asterism of three nearly perfectly aligned stars that make finding Orion easy. His head appears as one star, but binoculars easily separate them into three stars.
His right shoulder is marked by the red supergiant Betelgeuse, one of the largest and most luminous of all the stars we can see. It’s big, really big. If it were at the center of our solar system, its surface would extend beyond the orbit of Mars, engulfing Mercury, Venus, and Earth as well. It’s cooler than the sun, with a surface temperature of about 5600 0F. It boils and bubbles more violently than the sun, much more, which makes defining its exact surface uncertain.
The star Rigel, Orion’s left foot, is another supergiant, but blue-white. It’s much hotter than the sun, about 21,400 0F. Your roast wouldn’t need 3 hours to bake. A sword hangs from Orion’s belt; another line of three dimmer stars — apparently — but binoculars perform their magic again. Binoculars reveal that the center “star” of the sword is a large luminous cloud. The Great Orion Nebula is spectacular in amateur telescopes. It is a veritable stellar nursery where God is still birthing stars.
Within the cloud is the Trapezium, an asterism of four-young stars that are easily seen in small telescopes.
For me, Winter would not be the same without Orion and his faithful “dog” star Sirius. They are a beautiful sight that takes some of the chill out of a winter night. Enjoy!