Orion dominates the winter sky, and with good reason. His stars are bright, and he actually resembles (in stick-figure form, at least) the character from Greek mythology he is named after.
In February, you’ll find the constellation high in the south around 9 p.m. Its four brightest stars form a large rectangle standing on its end. Almost at the center of the rectangle formed from the four stars are three brilliant stars in a horizontal row – Orion’s belt.
Winter has the reputation of having the brightest stars of all the seasons of the year, but it actually doesn’t if you look at the whole sky.
What it has is Orion and his retinue. Orion’s main stars are bright, but they are no match for the head of his hunting dog Canis Major. Find Orion’s bright belt stars and use them as pointers down and to the left to find the nighttime sky’s brightest star. Sirius, the “Scorching One,” represents the dog’s head.
Find the belt stars again and use them as pointers up and to the right. You will discover the V-shaped head of Taurus, the Bull, with its bright, red, bloodshot eye, also known as the star Aldebaran.
Keep on going up and to the right and you will discover a small, dipper-shaped collection of six stars called the Pleiades, or Seven Sisters, perched on the Bull’s shoulder.
The stars in the rectangle that outline Orion’s body are bright enough to have been named by ancient Arab astronomers. Bellatrix (the Amazon Star), forms Orion’s left shoulder (his left, your right) Saiph (“Sword”) is Orion’s left foot, which makes no sense unless Orion had an uncharacteristic accident with his weapon.
Orion’s right shoulder is Betelgeuse, which may be an extremely corrupted form of an Arabic expression that means “the armpit of the giant.” (There is some dispute among scholars on the matter of Orion’s armpit. I am frequently amazed by some of the subjects under dispute by some scholars.)
Betelgeuse is a red supergiant, a star in its death throes that has expanded to incredible size. Although its mass is 20 times that of our sun, its volume is more than 160 million times greater. Betelgeuse is often characterized as a red-hot vacuum.
Rigel (left leg of the giant) is, yes, the left leg of Orion, putting it at the lower right as we look at him. It is a white supergiant, about 50 times as big as our sun. It is the seventh brightest star in the sky, shining with an intrinsic brightness of nearly 60,000 times the sun. The reason it looks fainter than the brightest star in the night sky, Sirius, is that it is a lot farther away.
Hanging from the left-most star of Orion’s belt is his sword.
Near the end of the sword is the most beautiful object to observe with a small telescope – the Great Orion Nebula. This bright patch is easily visible with binoculars. A telescope reveals complex swirls of growing hydrogen gas.
Orion holds his shield before him and above he brandishes his upraised club. In practically every culture on Earth, he has been called a hunter or warrior. North American Indians revered him as a great hunter of bears.
He predates the classical Greek civilization to the agricultural and even hunting cultures that preceded it. For them he was a kind of sky calendar. When he rose at dawn, it was taken as a sign of approaching summer and in the evening as a sign of winter. When he rose at midnight, it was time for the grape harvest.
Later, the Greeks thought of him as the son of the sea god, Poseidon.
He makes the standard mythological mistake. He falls in lust with the Seven Sisters, the Pleiades. The gods lift Orion into the sky, where the Greek deities seem to store all the characters they find annoying.
My sympathies go to the Seven Sisters. The gods also put them in the sky, where Orion must pursue them forever.
As long as humans have been looking up, they have recognized Orion. But just in the last 10 years, city lights have made it difficult to see his fainter stars.
Already the dimmer stars in the shield and upraised arm are impossible to see from most of Columbus. Even with the general increase of outside lighting, the dazzling outline of Orion and his retinue is still bright enough to cut through the haze of our lighting inefficiencies. Go out and see them some cold winter night. And take your friends and neighbors and your children and grandchildren while you still can.
Tom Burns is director of the Perkins Observatory in Delaware.