Crescent, NGC 6888

This wide-field image of the Crescent Nebula was taken at the National Science Foundation's 0.9-meter telescope on Kitt Peak with the NOAO Mosaic CCD camera. Also known as NGC6888, the nebula is a shell of gas that is being energized by the strong stellar wind from the Wolf-Rayet star WR 136, the bright star at the center of the nebula. It is located in the constellation of Cygnus, the Swan. Wolf-Rayet stars are very hot, massive stars that are blowing off their outer layers. In this image north is down and east is to the right. This image was created by combining emission-line images in Hydrogen-alpha (red), Oxygen [O III] (blue) and Sulfur [S II] (yellow).