Early Morning Posting
I managed to catch it in nearly full totality. A lunar eclipse is caused when the moon moves through the shadow that the Earth throws. They are not common occurrences, but far more common than the other type of eclipse where the moon moves between the sun and the Earth. Then before I packed the camera back up I noticed that to the southeast over the house, my old friend Orion was making an appearance. So I decided to snap his picture as well:
Orion is my favorite constellation. It has so much going on. It was this one constellation that inspired me as a child to take up astronomy as a hobby. Looking through a beat up old pair of hunting binoculars I could easily spy the odd glow around the Orion's sword stars and wondered what the glow was. Eventually I learned that it was the Great Orion Nebula, a pool of gas some 1500 light years away that spans an area hundreds of light years across. If you look at the photograph you can just see that there is an odd luminosity in the area of the sword stars. It is absolutely gorgeous to view in a moderate sized telescope. Here's a labeled version for you:
Orion is the most recognized constellation in the sky. More people can pick out Orion than can pick out the Big Dipper. The one shoulder star Betelgeuse is very interesting. If you look at the image,you will clearly see that it is a different color from the others. Betelgeuse is a red giant. If you were to place Betelgeuse at the center of our solar system, its surface would extend all the way out to the orbit of Mars. Betelgeuse is so large in fact that it is one of only a dozen or so stars that have been imaged as an actual disc. Further the disc has been imaged so well that Betelgeuse was the first star that has been imaged with "star spots" (structures like sun spots on our sun). Despite the fact that Betelgeuse is a whopping 310 light years away, when this star finally does go supernova (possibly leaving a rare oxygen/neon white dwarf), the light from the event will possibly be as bright as the full moon viewed here on Earth. There is another interesting note about Betelgeuse. Chinese records hailing from the 1st Century BC note the star as being white to yellow. Ptolemy however notes the star as being red in 150 AD. As a star uses up the hydrogen fuel in its core its color will change from white to yellow and finally to red. So that means that this star may well have entered its carbon burning phase in the frame of that time period.
Rigel on the other hand is a blue super giant with 17 times the mass of our sun. Rigel isn't anywhere near as large as Betelgeuse however. While Betelgeuse is 630 times as large as the sun, Rigel is only about 70 times larger than the sun. Rigel is about 913 light years way. Its light illuminates another nebula in Orion's area of the sky, the Witch Head Nebula. Rigel has a stellar partner, Rigel B which orbits Rigel (Rigel A) at a distance of 2200 AU (1 AU is the distance from the Earth to the sun or about 93,000,000 miles). Rigel B itself is a binary star. Its partner, Rigel V orbits Rigel B once every 9.8 days.
The main difference between the two stars, Betelgeuse and Rigel is the fuel that they are burning. Rigel is still burning hydrogen, the primary fuel for stars. Betelgeuse is burning carbon. The idea that a star burns fuel is a mistake. Stars do not burn anything. In fact they fuse atoms together to form other heavier elements. As a star ages it fuses more and more of its hydrogen into helium. If the star is large enough, there will be enough energy from gravity to fuse helium into carbon. Again if the star is sufficiently large, it will fuse the carbon in to oxygen. This pattern continues through neon then silicon and then finally with the largest of all stars, through sulfur. When I mentioned earlier that Betelgeuse may leave a oxygen/neon white dwarf that alludes to the fact that Betelgeuse is massive enough that it should be able to fuse all of its carbon into oxygen and then some of its oxygen into neon before it finally burns out... Reaches a point of stasis where very little further fusion is possible.
Welp I guess I've covered this well enough for a blog post... Oh, one more thing. Today is the 28th of August... Remember, buy some ammo!
UPDATE: Here's a really bitchin' picture that another amateur astronomer took of the recent lunar eclipse.