Barnard's initial catalog of dark nebulae, first published in 1919, described 182 entries and was superceded by a 1927 follow-up publication which was expanded to include 349 entries. These "dark nebulae" are believed to be the result of molecular clouds of dust and gas which are present in our line of sight and which absorb the starlight originating behind them, thus providing the earth-based observer working in the visible spectrum the illusion of a black "void". The famous Horsehead Nebula also appears in Barnard's Catalog as B33. This image is a 3 hour exposure on the night of September 28, 2011 with the Hyperion Astrograph. You can see the nebula near the top center where it appears there are only a handful of stars. Remember, the dark nebula is actually blocking the light from the stars that are behind it. Click on the image for a closer look.