Omega Cygni is a double star system and planet, in or near Federation space, and home to a native alien civilization. (TNG: "Conspiracy")
Harry Mudd once visited Omega Cygni, where he turned a handsome profit selling the natives their own oceans. (TAS: "Mudd's Passion")
Background
Omega-1 Cygni and Omega-2 Cygni are real stars, located in the constellation Cygnus (the location of Deneb), this system has been called Rukbah or Ruchba by astronomers on Earth. Omega Cygni was mentioned, misspelled "Omega Cyngi", as a small note on a very large star chart graphic created for "Conspiracy" (TNG). It was the image behind the chair in the room where Dexter Remmick was killed.