Deep-Sky Objects The constellation Canis Minor, reflection nebula M78, and the Witch Head Nebula (IC 2118)
Deep-Sky Objects, Stars Twin stars Castor and Pollux, the 9–12 Geminorum Cluster, and the Eskimo Nebula
Deep-Sky Objects If space is only a few degrees above absolute zero, how can hot nebulae gases from exploded stars stay warm for a long time?