- You may be looking for Magus III.
A Federation star chart depicting the location of Makus III
Makus III was the third planet in the Makus system. This system was located in the Alpha Quadrant, and was located in or near Federation space. (TNG: "Conspiracy")
In 2267, the USS Enterprise delivered medical supplies to Makus III, to be transferred to the New Paris colonies after a plague outbreak. (TOS: "The Galileo Seven")
Makus III was mentioned as a small note on a very large star chart graphic created for TNG: "Conspiracy". It was the image behind the chair in the room where Dexter Remmick was killed. It appears to be located within an outlined block, which may indicate that it was surrounded or was even a part of Federation territory at the time. It appeared to be near Gamma Trianguli and Deneb.