The Pipe Dark Nebula
The dark nebula predominant at the lower left of the above photograph is known as the Pipe Nebula . The dark clouds, suggestively shaped like smoke rising from a pipe, are caused by absorption of background starlight by dust . These dust clouds can be traced all the way to the Rho Ophiuchi nebular clouds on the right. The brightest star in the field is Antares . Many types of nebula are highlighted here: the red are emission nebula , the blue are reflection nebula , and the dark are absorption nebula . This picture has been digitally enhanced .