- You may also be looking for Aldebaron III
Aldebaran III was the third planet of the Aldebaran star system in the Alpha Quadrant and site of a Federation outpost. (Star Trek VI: The Undiscovered Country production art; TOS: "The Deadly Years")
In the star chart "The Explored Galaxy", the star Aldebaran was positioned between the Tholian Assembly and Romulus. Both were identified in DS9: "Call to Arms" as being located in the Alpha Quadrant.
In the remastered "Up The Long Ladder", the HMS New Zealand was assigned to a diplomatic mission to Aldebaran. Captain Jean-Luc Picard asked for ...all Earth deep space launches...with a destination in or near the Ficus sector. The computer listed launches that, according to Commander William T. Riker, didn't end up in that sector. Probably then, Aldebaran would be located in a sector adjacent to Ficus.
Prior to 2151, Earth ships had been operating within 90 light years of the Sol system. In that year, the Enterprise became the first ship to travel further than this distance. With the diplomatic mission to Aldebaran in 2135, Aldebaran III was probably located within this range. (ENT: "Two Days and Two Nights")