E.E. Barnard visually discovered IC 4604, the Rho Ophiuchi Nebula, around 1883 using his 5" refractor. See notes on IC 4603.

Caroline Herschel, in a letter to her nephew John Herschel, wrote she "once heard your father, after a long awful silence, exclaim "Hier ist wahrhaftig ein Loch im Himmel! [Here is truly a hole in the heavens!]”. She added her brother returned to this unique region several nights over several years. Caroline urged John to search for this object in the lower part of Scorpion during his trip to South Africa. John sent Caroline a letter from the Cape of Good Hope dated 22 Feb 1835 in which he stated the region near Rho Ophiuchi contained fields “without the smallest star." In 1928 Johann Hagen, director of the Vatican Observatory, claimed William Herschel's "Hole in the heavens” referred to B86, but Joseph Ashbrook stated it referred to the Rho Oph region in an "Astronomical Scrapbook” column.

400/500mm - 17.5" (6/30/00): this northern section of the Rho Ophiuchi nebula surrounds three bright stars including mag 5 Rho Ophiuchi (a close double at 3" separation) and two mag 7 stars 2.5' N and WSW. The glow appears most evident around the bright star. The dusty surrounding field (Barnard 42) is nearly empty of stars.

Notes by Steve Gottlieb