Changing Nebulae-An Animation

This is a follow up to my post the other day of NGC 2261, Hubble's Variable Nebula.
Jeff Hapeman and Joe McBride generously shared their versions of this nebula in response and that started me wondering if changes could be seen over the course of these images.
Just for the grins, and with apologies to Jeff and Joe for hijacking their images, I made a gif of these three images morphing into one another. This is, of course, in no way accurate or scientific. I only made a feeble attempt to normalize the background and brightness levels.
One must remember that these images were taken with different scopes, different skies, and different processing. At one point, some stars 'materialize' in one corner because of missing data.
The gif begins with Jeff's image from 2002, then Joe's of 2005, and finally mine from 2006.
(Animation is about 700kb)
http://members.cox.net/dakoan/NGC2261.gif
Let me know what you think.

dan kowall

That's great fun!

Tom

Great job.

thats way cool dan. I think despite the different scopes, cameras, exposures, processing etc, you can definately see shadows being cast across the nebulosity.....

Hi all --

I'm guessing that what's changing is the distribution of light as it progresses thru the nebular gas. That would mean that light output of its source is what has changed (increased) and not the nubular gas itself. Opinions?

The animation is beautiful.

Bob Polcyn