A map of the Talosian system
Talos on a Federation star chart
Talos V was the fifth planet in the Talosian star system. This planet orbited the binary stars of Talos at a distance of over 3.2 astronomical units. The location of Talos V was depicted on a Federation star chart in 2293. It was located near Andor, Eminiar, and Phylos. (TOS: "The Cage"; Star Trek VI: The Undiscovered Country)
Background Info
This chart was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were: TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game" and DS9: "In the Hands of the Prophets", "Cardassians".
The planet was never mentioned in dialog; this name came from a map of the Talosian system.|Next to this planet, there was a small white dot. This might represent a moon; however, the best resolution of this map makes the determination uncertain.
According to Star Trek: Star Charts, on page 40, Talos V was classified as a Class D world.