Light Echo

Okay, go here, and see a really cool compilation of pictures morphed into a movie.

I've been watching the progression of these pictures since 2002, and it's really amazing to see how rapidly this shell has grown in less than seven years.

Here it is without the morph.

And then a quote from another compilation:

The sequence of images in this video depicts the variable star V838 Monocerotis (or V838 Mon) - a so called 'red supergiant' star in the constellation of Monoceros - exhibiting a phenomenon known as the light echo effect.At first glance, the image sequence appears to be that of an expanding cloud of dust and gas moving outward from the star. Actually, the cloud already surrounds the star, but had always been too thin and tenuous to be visible, and so was never detected up until just recently.When V838 Mon underwent a sudden expansion and then a contraction (giant and supergiant stars have a tendency to do this!), it flared-up giving off a bright flash of light in January of 2002. The expanding sphere of light traveling outward from the star lit up successive surrounding cloud layers as it proceeded to travel through them, rendering them visible for the first time.The diameter of the widest image is of the order of about five light years. The images were therefore taken over a period of about two and a half years. Each image was taken around 7 to 8 months apart.

And then the Hubble site.