Sunday, January 9, 2011

FROM WHITE DWARFS TO RED GIANTS Traveling the Night Skies of Winter

With my feet planted solidly here on a speck of canyon country in Southern Utah, in the intense dark of a mid-winter night, I can see “forever”. From horizon to horizon the marvels stretch across the heavens in a visual display which has been played out since a “beginning” we can only imagine; from stars that are so old in celestial time they are in their last star-moments of life, to others so “new” they would not yet have been visible to earth’s dinosaurs.
If there is one dominating figure among the constellations of winter, it would be Orion, the great “hunter” of Greek mythology. My eyes automatically turn to this overpowering figure as I step outdoors on any clear night. It is like an old, dependable friend reminding me of the few certainties of earth life and of the age old connection between humankind and the night skies. The grand scale of this mythical figure erases any need for telescope or binoculars, unless one is focusing on the great Nebula which seems to hang from Orion’s belt, like a glowing sword; one of the most magnificent of such astronomical sights. At the upper left “shoulder” of the hourglass constellation as viewed from earth is the red supergiant star known as Betelgeuse , which is the size of 800 of our Suns and probably approaching the end of its long life. It lies about 520 light years away and glows with the brilliance of 1500 “suns”.
The right foot of Orion as viewed from earth is a blue giant named Rigel (“foot” in Arabic), which is twice as far from earth as Betelgeuse, but whose brightness shines with a luminosity of 55,000 suns! Rigel is actually a “double star”; twins bound together by gravity and birth. (Probably 80 % of all stars in our galaxy are actually “doubles”, our own sun being an exception.)
The three bright stars which make up Orion’s belt, point directly to Sirius, the “Dog Star” in Canis Major, the brightest star in the heavens. A close neighbor of ours at a distance of only 8.7 light years and a key to human navigation since ancient times, Sirius also has a white dwarf companion star with which it rotates once every fifty years. Such an impact has this conjunction had upon life on earth that it is now believed that the great pyramids of Giza were laid out in the exact similitude of Orion’s belt, with the Milky Way representing the river Nile.
Another “old friend” in the winter sky is a cluster of stars we call “The Pleiades”, (Seven Sisters in Greek). This open cluster figures importantly in the history and mythology of many cultures: To America’s Cherokees it is known as Ani’tsutsa or “The Boys”, and among many tribes it ushers in cleansing ceremonies, and the time for naming newborn children. In Japan, the name for Pleiades is “Subaru”, and the symbol for the famous car-maker contains those famous stars.
While that shiny “thumb print” high overhead in midwinter is easily seen with the naked eye, binoculars will reveal the seven brightest members of this cluster, and suggest that there are really many more hiding in the luminescence – actually several hundreds. 440 light years from earth, what you are actually seeing in the Pleiades is a star “nursery” in action; a young star system unfolding from what fairly recently (in celestial time) was a dust cloud left over from a supernova. The group of bright stars are physically related, and are moving in the same direction, although future generations of earth people will notice a wider separation between them.
Not to be forgotten in all of this is our own captive satellite – the Moon – upon which rests the earth’s tidal system and earth life itself as we know it. As it travels across our night sky along a circular path known as the great ecliptic, it presents us with an ever-evolving image, and keeps company with other planets of our solar system whose perceived journeys take them within a few degrees of the moon’s route. In January in fact, the Moon and gigantic Jupiter will appear almost in alignment for a few hours. The full moon of January has been called “The Hard Times Moon” by Maine’s Penobscot people, “The Melting Snow Moon” of the Navajo, and “The Whirling Wind Moon” of the Narragansett. To early settlers, it was known simply as “The Wolf Moon”.

Often mistaken for “The Little Dipper” because of the relationship of the brightest of its primary stars, the Pleiades has been known as “the Cradle”, the “Seven Sisters”, and “The Boys”. They lie in a very young corner of our galaxy and keep us company through the long cold nights of winter.
NASA Photo

A full moon rises out of the Atlantic ocean along Maine’s mid-coast, providing us with one of Nature’s most powerful illusions, seeming to be larger than it is because of its closeness to our horizon.
Al Cooper Photo

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