I published a picture of the galactic core a day ago. One of the comments on the post struck an interesting cord.
+Natalie K. reminded me that stars sparkle
When I take dark sky pictures, very bright stars burn into the picture. If you magnify the picture - the image of the star starts to expand into nearby pixels, making the star appear bigger. However, looking through a large telescope even very bright stars are single points of light (although very bright). These points of light dance, moving slightly, and changing brightness - according to atmospheric conditions.
So I went back to pictures of the sky and attempted to capture this in high quality images. I then examined what was happening and tried to reproduce the effect in the attached animation.
The animation consists of a master frame - with two overlays (in total creating 4 frame variations) - creating the illusion of tighter stars with some atmospheric movement - twinkle :)