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Re: APOD: Scintillating (2011 Apr 28)

Posted: Fri Apr 29, 2011 3:24 pm
by Ann
Great picture and a great animation, Noel! Thanks!

Ann

Re: APOD: Scintillating (2011 Apr 28)

Posted: Mon May 02, 2011 9:36 am
by mastrulo
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. :-D
Hi,
That's part of the whole picture that I simply don't understand, why did those points of light (stars) also scintillate?
I used photoshop many moons ago ver. 3.something. I do not profess to know much about its power, But I asked the question, if light is distorted by the atmosphere, then should not all light do so with varying wavelengths being distorted/scintillated in different ways?
The other, and I believe is the most important point, the shutter was open for 10 seconds. I'm no mathematician, nor a qualified Astronomer, but I passed with As and A+s in all my Maths and physics.
Many many moon ago, I am an authority on Telecommunications (35 years). But from my slowly fading memory, I asked the question. Look at any 10 second exposure, how many points elongated do you see? then if the camera is swung why are there only 2 points.
I am only asking, and I believe very good questions.
If I look up at night with a camera I cannot Isolate any single point of light let alone 2 in the same frame.
That is my only question.
I don't get it.
I thank all the replies, I know the 'CRO' Lysaght display well, period/time(?).
But the question is to the whole and not to the 2 points alone. Would a camera and 10 seconds of an open shutter produce 2 points of scintillating light.
I ask with the scientific principle, if it can be reproduced by anyone (all) then HUMBLE PIE I WILL GLADLY EAT.
Thank you.
No Offence indented.
Kindest regards.
Tony Mastrullo.

Re: APOD: Scintillating (2011 Apr 28)

Posted: Mon May 02, 2011 2:28 pm
by Chris Peterson
mastrulo wrote:That's part of the whole picture that I simply don't understand, why did those points of light (stars) also scintillate?
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.
Look at any 10 second exposure, how many points elongated do you see?
A typical ten second exposure of the night sky with a modern digital camera will show hundreds of stars.
then if the camera is swung why are there only 2 points.
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.
If I look up at night with a camera I cannot Isolate any single point of light let alone 2 in the same frame.
Sure you can- easily. Try it.