The nebulae of Ophiuchus
The region of the sky in and around Ophiuchus fascinated William Herschel; E. E. Barnard repeatedly returned to it in an attempt to understand the structure of the Milky Way. If you spend a little time with the constellation, then you’ll begin to understand some of the historical misunderstandings that arose here. Observing this region, Herschel reacted with shock as he swept past such objects as the globular star clusters M80 and M4 only to enter what would become known as the dark nebula Barnard 42 and the bright nebulae IC 4603 and IC 4604. He proclaimed that he’d discovered a “hole” in the sky without a star to be seen. William’s sister, Caroline, wrote to her nephew,
