The Summer Triangle is an asterism composed of brilliant Vega at the top left of the frame, Deneb at lower left and Altair at right. The rich star clouds and dark nebulae of the Milky Way dominate the image. The Great Rift in the Milky Way runs through the star clouds in Aquila at upper right through Cygnus at lower left. Le Gentil 3, a large dark nebula, is in the bottom left corner of the image. The Northern Coalsack, another large dark nebula, lies to the right of Deneb and marks the beginning of the Great Rift. The NGC 7000, the North America Nebula, is the bright red hydrogen-alpha emission nebula just below Deneb. Another bright emission nebula, IC 1318, the Butterfly nebula, surrounds Sadr, Gamma Cygni, at the heart of Cygnus, the Northern Cross.