Drifting through the Orion Arm of the Milky Way is the California Nebula, a cloud of hydrogen and sulfur gases, with a whispy blue veil of oxygen. More than 100 light-years long, this "California shaped" mass is not far from the Pleiades star cluster in the constellation Perseus. I composed the image in a portrait orientation, with the cloud rising across the frame to emphasize the movement of the nebular folds.
 
21.1 hours total exposure of ionized hydrogen, oxygen, and sulfur emissions