Marcus II
Marcus II was the inhabited second planet of its star system. This planet was located somewhere in the Alpha or Beta Quadrant and was the homeworld of the noted artist Sten. (TOS: "Requiem for Methuselah")
Appendices
Background information
This planet was only mentioned in dialogue.
Apocrypha
According to the section on the system in the "Star System Data" appendix of the "Introduction To Navigation" booklet included with the first published volume of Star Trek Maps, the Marcusites never developed spaceflight, instead fighting a series of devastating nuclear wars. Theirs was described as being, by the late 2260s, a dwindling population that had become noted mainly for its artistic achievements, including those of Sten.