NGC281 - PACMAN NEBULA

The Pacman Nebula is an emission nebula located in the constellation Cassiopeia, approximately 9,200 light-years from Earth. It earns its playful nickname from the dark lanes that cut into its roughly circular glowing form, creating a shape reminiscent of the famous video game character. The nebula is associated with the open cluster IC 1590, whose central multiple star system HD 5005 provides the ultraviolet radiation that ionizes the surrounding hydrogen gas. This central star system includes an O-type star that is the primary energy source driving the nebula's luminosity. NGC 281 was discovered by Edward Emerson Barnard in 1883 using a wide-field telescope, and it was one of the first nebulae to be discovered photographically. The nebula contains several prominent Bok globules, dense knots of dark molecular gas and dust that appear as dark silhouettes against the bright emission background. These globules are of particular scientific interest because they represent the earliest stages of star formation, where dense clumps of gas are contracting under their own gravity before igniting as protostars. Some of the Bok globules in NGC 281 show evidence of ongoing photoevaporation, where the intense radiation from the central cluster is slowly ablating their outer layers while their dense cores continue to collapse. The nebula also features dramatic dust pillars and bright rimmed clouds along its periphery, where the expanding ionization front meets denser material in the surrounding molecular cloud. The Pacman Nebula is visible in moderate amateur telescopes as a faint, diffuse patch surrounding the cluster stars, but its full structure with the distinctive dark lanes becomes apparent only in photographs or with narrowband filters.

Located approximately 9,200 light-years away, the nebula spans about 35 light-years across and contains multiple Bok globules ranging from 0.5 to 1.5 light-years in diameter.