Gamma Arigulon

Gamma Arigulon was the primary of the Gamma Arigulon system. This star was located in a sector of the Beta Quadrant.

In 2367, the starship LaSalle detected radiation anomalies coming from the star's system. The USS Enterprise-D was sent by Starfleet Command to investigate these anomalies. After finding no abnormalities in the star's radiant energy, the Enterprise was preparing to launch two class 1 probes for a more detailed investigation of the sun when K'mpec's attack cruiser decloaked. (TNG: "Reunion")

This star was only mentioned in dialogue.
This star was not named in the episode; rather, the name came from StarTrek.com. [1](X)
The quadrant of origin for this star was based on a line of dialog from the episode, where Data said, If true, it would represent a fundamental shift of power in the quadrant. in response to a question from William Riker about a possible alliance between the Klingons and the Romulans. Both species were based in the Beta Quadrant.