The Orion Nebula
The Galaxy >
Rising in the east after sunset this month is a well-known constellation – Orion, the Great Hunter. Orion is easily recognized as the monstrous quadrangle of stars with “the belt” of three stars dissecting it.
Orion, it turns out, has a lot of great stuff to look at. In this constellation
you can see huge stars near death, show-off adolescent stars, and a nursery!The biggest, baddest star of them all is Betelgeuse. Big B is that reddish star in the “upper left” of the rectangle of stars. The name comes from the Arabic Ibt al Jauzah, roughly --- but poetically --- translated “the Armpit of the Big Guy.” (Ancient Arabs astronomers named many of our stars.)
Almost all stars are so far away that they are mere pinpoints of light. Not Betelgeuse. It is far away to be sure (over 400 light years) but it is so unimaginably big (more than 1500 times bigger than our sun) that the Hubble Telescope can actually make out some surface features!
If we could put Betelgeuse in the place of our sun, it would swallow all the planets out to Jupiter and beyond!
But, sadly, it has one foot in the grave. In the next several thousand years it is scheduled to supernova. That’s when a gigantic red star runs out of fuel and in a series of events blows itself to smithereens.
Rigel (from the Arabic “left leg”) is that really bright star at the bottom right of Orion. How bright? Try 60,000 times brighter than our sun, and a hundred times bigger. But the credo amongst stars in the heavens is “live fast, die young.”
Alas, poor Rigel only has millions of years left before it goes the way of big brother Betelgeuse and supernovas into oblivion.
The three that make up The Belt are also fast-burners. From left to right, Alnitak, Alnilam, and Mintaka are all burning their fuel fast and furious and will be detonating relatively soon – boom! boom! boom!
Below
the Belt is one of the best star nurseries in the biz. Good eyes will
see a blurry area, good binoculars will see a furry star, good telescopes
will see a tiny foursome of stars surrounded by an immense cloud of luminous
gas.The four stars are the Trapezium, four infant-toddler stars. But these bad boys are burning with such intensity that Hubble has shown that they are sweeping the whole area clean of gas and dust, effectively cleaning their nest. And they, like their big brothers Betelgeuse, Rigel, and the Belt stars, are destined for a speedy demise.
The stars of Orion are all located in the same neighborhood of our galaxy. Astronomers believe they are all related, made from the same gigantic cloud of gas. But the whole neighborhood, like most neighborhoods in southern California, is a very recent development.
If you could have walked the earth when dinosaurs were in charge, you wouldn’t have seen Orion, or, for that matter, most of the constellations we know and love. Nearly all of them are made of the “live fast, die young” stars. The skies were entirely different then.
And if you manage to stay healthy and stick around for several million more years you’ll have a whole new zoo of constellations in our ever-changing skies.
So go out this month and enjoy Orion and the others now while you can – before it’s too late!
Stunning images of the stars of Orion can be found at firstlightastro.com. Click on iColumn.
Until next time, clear skies!
Mark Ritter, like Orion, has an armpit and a left leg. He can be reached at ritter@firstlightastro.com
Posted by Administrator at 2001.01. 7 08:53 AM | Comments (0)
