V838 Monocerotis was a star system surrounded by a nebula in the Alpha or Beta Quadrant. It was a binary star system with a pair of stars. V838 Monocerotis was located in the constellation Monoceros and was approximately 19,000 light years from Sol.
An image depicting V838 Monocerotis was scanned by the Talosians as they reviewed the library computer files on board USS Enterprise in 2254. (TOS-R: "The Cage")