American Public University System’s Richard G. Trefry Archives contain documents and items that represent the history, development, and progress of the institution as its recorded memory.
The Horsehead nebula is part of the larger Orion nebula; it is a dense, dark nebula where star formation is taking place. The nebula can be seen in relief against the bright background of the IC 434 emission nebula.
The Swan Nebula is a region of ionized hydrogen, known as an HII region, in the constellation of Sagittarius.
The Trifid Nebula is named for the three bright sections delineated by the dark nebula at its center. It is a large star forming region.
NGC 281 is an emission nebula located in the constellation Cassiopeia. It is part of the Perseus Spiral Arm in the Milky Way Galaxy.
The Wizard Nebula consists of a young open cluster surrounded by a gas nebula in the constellation of Cepheus.
The Rosette Nebula is an HII region closely associated with an open cluster (NGC 2244) in the constellation of Monoceros.