Photo by Laurence Mohr. The Bubble Nebula (Caldwell 11) located ca. 10,000 light years away in the constellation Cassiopeia. The affect of the hot central star on the surrounding hydrogen gas is clearly visible – causing the gas to glow like a neon sign and forming it into a bubble with its stellar wind. 36 exposures at 10 min each; ISO 800; EdgeHD 1100; f/7; taken in Brooklyn, Wisconsin.