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View Full Version : Is something going on with Sirius?



Lady Krimson
2009-Nov-19, 05:47 AM
I was watching the sky tonight and saw Sirius flickering madly and flashing red, blue and green. I took some video of it, and I looked up any breaking news. There was nothing to be found, however. I know it doesn't sparkle like that all the time. Does anyone have any news?

Nick Theodorakis
2009-Nov-19, 05:51 AM
It can do that, particularly when it's low in the sky. It's an atmospheric phenomenon. See:

http://www.earthsky.org/tonightpost/brightest-stars/sirius-the-brightest-star

Nick

Durakken
2009-Nov-19, 05:55 AM
It was being Sirius!

Sorry, had to say that joke...

Lady Krimson
2009-Nov-19, 05:58 AM
I see. Thank you. I am new to the "mechanics" of astronomy.

Nick Theodorakis
2009-Nov-19, 06:09 AM
Welcome to the board, btw.

Nick

astromark
2009-Nov-19, 08:42 AM
Earths atmosphere is a gas. Its moving and has much change in density as you climb up through it. From 14 psi at sea level to absolutely 0. As light arrives and penetrates our air its path is distorted and what is refereed to as atmospheric aberration. This movement of atmosphere can be compensated for by adaptive optics or just viewing from a high and dry place...or from space. Looking at objects near the horizon makes this light image distortion worse. You are looking through a large slice of air. Looking more directly over head helps clear the image.
So it was not Sirius twinkling. It was the atmospheric aberration. and Welcome...
.

Lady Krimson
2009-Nov-19, 06:44 PM
Thanks everyone. I thought it was absolutely beautiful, so I tried to get it on video. Maybe I'll post it later.