Stars in Orion's belt?
From what I can remember of my seventh grade science astrolab unit, the three stars in Orion’s belt point downward to a bright star. Tonight in Brooklyn it was very bright. I made my wish on it! What star is it? Is it a planet? I thought I saw it “twinkling” and I thought that stars “twinkle” and planets do not. Maude, where are you? Harold.
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Of course, It’s Sirius, the dog star. Didn’t know that it was actually a binary star system..how Star Trek! Here’s a question. I heard once that a tribe in the Americas used a binary star to tell which of their warriors had the best vision. If you could see that there were two stars it meant you were the best or something, Was that Sirius?
Also, stars always twinkle, planets sometimes do =)
Basically, stars are “point sources” (because they are so far away) when they enter the earth’s atmosphere, so very small disturbances in the upper atmosphere can disturb the apparent brightness of a star, making it twinkle.
Larger atmospheric disturbances can make the planets twinkle too, particularly around cities.
(Oh, and you may be thinking of the stuff surrounding the Dogon People: http://en.wikipedia.org/wiki/Dogon_people —scroll down to mythology)
The classic astronomical vision test, historically (not just for the Dogons) and presently, is of the visual double star in the handle of the Big Dipper. Look at the star, second from end of handle; it is easy to see – Mizar. Barely touching it is a little guy called Alcor.Can you spot it w. yr naked eye? Fun to check out w. binoculars.
Mizar
I can’t give you compass points since the Big Dipper is a circumpolar asterism and rotates during the night around the North Star (Polaris) at the end of the handle of the Little Dipper. It, along w. the Little Dipper, and opposite it, Cassiopaeia (the W) are up all night all year.
Sirius is the brightest star in the sky. The only things that will glitter more brilliantly (other than the moon) are Jupiter and Venus. Now Venus is ablaze as the morning star (pre -dawn in the SE). It can be seen as a crescent shape w. 8×42 binocs, propped on something to remove hand tremor.
The interesting slightly blurred stuff hanging below Orion’s belt is his sword and is a famous hotbed, or birthing room, of new stars.
Here’s a good relative view of both Orion and Sirius.
Orion
Everything in the sky will twinkle from Brooklyn; air pollution is bad there.
If you care about the math, (Harold, I am sure that you do), Venus at its apparent brightest, is about 23 x brighter than Sirius. I believe that it is 2.512^3.23 (Would someone who really knows what he is doing, please check my math?)
Each apparent magnitude increase is the 5th root of 100=2.512. Venus now is about -4.7 mag and Sirius, -1.47 – - 1.47 = 3.23. Have I got that right? : 0
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