By David Ward
The giant is back. That big old guy who hangs out with us in the winter is raising himself above the horizon. Look for him low in the southeast just after it gets dark. He is lying down then, but later in the night he will be in all his glory standing upright in the south. Most early cultures saw this grouping of stars as a giant figure. The ancient Greeks called it Orion, a huge and handsome hunter who boasted he could kill every animal on earth.
Orion has more bright stars than any other constellation in the sky. He straddles the celestial equator and can be seen from any point on earth, even from both the poles. No wonder he is the most familiar constellation in the heavens.
We do not usually think of color in the night sky, but Orion gives us a chance to glimpse the different hues of the stars. Look at the bright star on the left of the constellation. Can you see it’s ruddy reddish color? Its name is Betelgeuse, loosely translated from Arabic meaning “armpit of the giant.” Then look diagonally across Orion at the bright blue white one. That is Rigel, “the foot.”
Color in a star is an indication of age. The reddish color of Betelgeuse indicates a star right near the end of its life cycle. It is huge, vastly larger than our sun, swelling and shrinking, like a dying old man wheezing and gasping for his last breath.
In perhaps as little as 20,000 years, the fuel that has stoked the nuclear furnace deep within its core will be exhausted. The crushing one-way force of gravity will overcome the giant star. Within a few seconds Betelgeuse will collapse in on itself then rebound outward in a supernova explosion. For a few weeks it will shine brighter than all the 300 billion stars of our galaxy combined, a brilliant beacon visible for a billion light years across the universe.
In the end gravity will win. The once mighty Betelgeuse will be reduced to one of the strangest inhabitants of the universe, a tiny black hole, cold, dark, insanely heavy, never changing for all eternity.
Blue-white Rigel, on the other hand is in the flower of its youth. Shining 60,000 times brighter than our sun, it is gobbling up its fuel like a reckless teenager with no thought of tomorrow.
Rigel will only last a few tens of millions of years, not nearly enough time for any planets it might harbor to come up with the miracle of life.
Be sure to look for Orion’s famous and distinctive belt, a trio of bright stars that the ancient Arabs referred to as “the string of pearls.” These are all stellar behemoths shining tens of thousands of times brighter than our sun.
Lots of planets
January is a great month for planet viewing. Most obvious is Venus dazzling us in the western twilight sky. Look to her upper left for much dimmer and reddish Mars. If you are up before dawn, Jupiter is shining almost as bright as Venus high in the east. Lower down in the east look for Saturn just before it starts to get light.
If you missed Mercury in December, you get another chance in January, although you will have to be an early riser to catch this seldom seen little planet.
If you have never seen Neptune, the most-distant major planet of our solar system, there is a great opportunity coming up. It is invisible to the naked eye and most of the time difficult to find, lost among the countless stars of our galaxy.
On Dec. 31 the two worlds were closer together in the sky than they have since the year 1305 AD. You will need a telescope to spot Neptune but the pair will be right next to one another. At almost 3 billion miles distant do not expect Neptune to rock your world. It will look like a pale blue-green dot.
On Jan. 4 the earth reached that point in its orbit known as perihelion, our closest approach to the sun for the year. Will someone tell me why it is so darn cold?