Thor’s Helmet is an emision nebula in the constellation Canis Major. The nebula is approximately 3,670 parsecs (11.96 thousand light years) from Earth and is 30 light-years in size. The central star is an extremely hot star thought to be in a brief pre-supernova stage of evolution. It has interactions with a nearby large molecular cloud that are thought to have contributed to the complex shape and curved bow-shock structure of Thor’s Helmet. This image is comprised of over 1200 sub-images (10-second exposures) under Bortle 6 skies.