Seeing double


Chris Schur from Payson, Arizona

The famous Double Cluster in Perseus lies at the center of this deep wide-field shot, which spans nearly 8°. The two open clusters (NGC 884 and NGC 869) are separated by roughly 0.5°, or the width of the Full Moon. The red nebulosity that fills the frame is the faint glow of hydrogen gas, only visible in a deep exposure like this one, which comprises 15 hours of exposure with a 2-inch f/3.5 scope and one-shot color camera. (Click here to see a close-up view of the Double Cluster taken by this imager at the same time.)