In this deep image of Cygnus, Deneb -- its brightest star -- lies toward upper left, while Albireo, at the head of the Swan, is at the lower right corner. The Milky Way runs down the middle. Reddish interstellar gas clouds (nebulae, one of which is called IC 1318) surrounds Sadr, the star at center, while the North America Nebula lies to the left of Deneb. P Cygni is a massive, erupting, "luminous blue variable," 61 Cygni is the first star whose distance was measured, the Cygnus Loop (part of which is only barely visible) is the remnant of an ancient exploded star, and Cyg X-1 is a blue supergiant that has a black hole companion, the pair radiating powerful X-rays as a result of mass transfer from the supergiant to the black hole.