Golden Wave

Arcing across the autumn night sky here in central California, the California Nebula is a cloud of hydrogen and sulfur gases and dust that has a faint, wispy veil of oxygen. This was a long project. The nearly 43 hours of photographic exposures needed to make this image were collected during the fall months of 2018, 2019, and 2021.
 
42.9 total hours exposure of RGB visible light, plus hydrogen, oxygen & sulfur emissions