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skrap1r0n
2004-May-06, 04:04 AM
Why does Sirus seem to twinkle so much more than other stars? Is this because its a double star or is there another reason?

aurora
2004-May-06, 05:10 AM
it is because it is brighter than any of the other stars, and also you are viewing it when it is fairly low in the sky (looking at objects near the horizon requires you to look through more of the Earth's atmosphere than when looking at a star near the zenith.)

The BA has a page on star twinkling if you search his web site.

space cadet
2004-May-06, 05:15 AM
I've noticed that too, but I really doubt that twinkling has anything to do with binary systems. Twinkling is caused by small pockets of shifting air in the earth's atmosphere, which distorts the light. My theory is that Sirius seems to twinkle more because it's larger than the other stars and thus has more light to be distorted and is therefore more noticeable; also it's currently quite low on the horizon and therefore its light must travel through more of Earth's atmosphere to reach us.

edit: aurora you beat me to it lol

Brady Yoon
2004-May-06, 06:05 AM
Aurora and Space Cadet pretty much said it all. :D A follow up question. Why do stars twinkle in multiple colors? :-?

Maksutov
2004-May-06, 06:17 AM
Aurora and Space Cadet pretty much said it all. :D A follow up question. Why do stars twinkle in multiple colors? :-?

Atmospheric refraction. The different air densities act like mini-prisms. If you want to see a really good show right after sunset, track from Sirius over to Betelgeuse, a red giant. As it approaches the horizon, it's like a kaleidoscope!