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Old 13-02-2017, 05:43 PM
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Shiraz (Ray)
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Join Date: Apr 2010
Location: ardrossan south australia
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Quote:
Originally Posted by Slawomir View Post
I am wondering about magnitude of these fluctuations in terms of pixel brightness within a galaxy. My guess is that these are minuscule and it is most likely that shot noise (as well as noise from the camera) normally drowns them, and one would possibly need unusually long integration to quantify these fluctuations. I am talking amateur imaging of course.
Not sure Suavi. From reading, SNR of maybe 5 is adequate for the surface brightness fluctuations to be noticeable with a close galaxy - my system will do that quite easily in a few hours with a typical sky. The source papers are a bit heavy for "idle curiosity" reading, but, from a skim over, it seems that the effect is noted in very short (eg 1 minute) images from big scopes at 1 arcsec seeing, so it does not feel like it is stretching thing to assume that we will see similar in multi-hour images at 2 arcseconds. In any event, I started digging around because I ran into "noise" that did not smooth out with more exposure - I now think that I may have already seen this effect on a few galaxy images (this one in particular http://www.astrobin.com/full/276705/0/?real=&mod=). cheers

Last edited by Shiraz; 13-02-2017 at 05:59 PM.
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