Sidr, Gamma Cygni (γ Cyg) is a yellow-white supergiant star located in the constellation Cygnus. With an apparent magnitude of 2.23, it is the constellation’s second brightest star, after Deneb. Sidr lies at an approximate distance of 1,800 light years from Earth. It is the star that marks the intersection of the Northern Cross, a bright asterism that dominates the summer sky in the northern hemisphere. Sadr lies in a rich field of the Milky Way and is surrounded by the diffuse emission nebula, also known as the Gamma Cygni Nebula or Sidr Region.