Before this nebula was observed by Hubble, it was referred to as “The Blob.” 🙃 Few features of Nebula 81 (N 81) could be seen from ground-based telescopes, so astronomers weren’t sure if just one or a few hot stars were embedded in the cloud, or if it was a stellar nursery. But the Hubble Space Telescope’s high-resolution imaging of the object in 1997 showed that the nebula contains numerous young, white-hot stars. These massive, recently formed stars inside N 81 are losing material at a high rate, sending out strong stellar winds and shock waves, and hollowing out a cocoon within the surrounding nebula. The two most luminous stars, seen in the Hubble image as a very close pair near the center, emit copious ultraviolet light, causing the nebula to glow through fluorescence. Outside the hot, glowing gas is cooler material consisting of hydrogen molecules and dust. Normally this material is invisible, but some of it is silhouetted against the light from the hot gas background, as long dust lanes and a small, dark, elliptical-shaped knot. The young stars formed from this cold gas and dust through gravitational contraction. #Hubble #nebula #HubbleHeritage #blob #stars Credit: NASA and the Hubble Heritage Team (STScI/AURA).