Re: APOD: Scintillating (2011 Apr 28)
Posted: Fri Apr 29, 2011 3:24 pm
Great picture and a great animation, Noel! Thanks!
Ann
Ann
APOD and General Astronomy Discussion Forum
https://asterisk.apod.com/
Hi,StarCuriousAero wrote:This is a beautiful image, and it doesn't look photoshopped at all, I have no idea what that guy was complaining about. You can actually see two additional stars, lower left AND lower right, but I have no idea which one it is, I'll refer that question to someone else.
Also, thank you Neufer for reminding me of Lissajou orbits, it's only been 2 years since I'd thought about them last but had already almost completely forgotten about them, haha. It's a shame I don't use more of the stuff I learned in college, but such is life. Pretty much any orbit utilizing the Lagrange points is pretty darned fascinating though, it's a shame they aren't used more often, YAY for JWST!! Can't wait for launch.
Both planets and stars show scintillation. The effect is just larger with stars because of the narrower cylinder of atmosphere their light passes through in reaching the ground.mastrulo wrote:That's part of the whole picture that I simply don't understand, why did those points of light (stars) also scintillate?
A typical ten second exposure of the night sky with a modern digital camera will show hundreds of stars.Look at any 10 second exposure, how many points elongated do you see?
Well, in this case there are actually a few stars visible, not just two. But the reason most of the stars disappear is because even though the shutter was open for ten seconds, it isn't a true ten-second exposure. That's because with the moving camera, the stars don't stay on the same pixels for the full exposure time. Any one pixel is illuminated for only a fraction of a second.then if the camera is swung why are there only 2 points.
Sure you can- easily. Try it.If I look up at night with a camera I cannot Isolate any single point of light let alone 2 in the same frame.