Bubbles Within Bubbles

Today's Astronomy Picture of the Day brings us to NGC 7635 in the constellation of Cassiopeia. Popularly known as the Bubble Nebula, subtle detail teased out of this image shows a series of bubbles as the nebula's central star pushes against the nebular gas. Cassiopeia is a wonderful target for low power/rich-field telescopes or binoculars during fall and winter.