Tau Cygna

Tau Cygna was the primary for the Tau Cygna system. This system was found inside the de Laure belt in the Alpha or Beta Quadrant. It was 5,000 or more light years from Sol.

According to Section 133, Paragraph 77 of the Treaty of Armens, the fifth planet of Tau Cygna had been ceded by the Federation to the Sheliak Corporate. (TNG: "The Ensigns of Command")

This star was only mentioned in dialogue.
In the Star Trek: Star Charts ("United Federation of Planets II"), Tau Cygna was identified as an orange star in the Alpha Quadrant.
In the Bayer designation, which was a system of stellar classification, the Greek letter indicated the brightness of a star in a constellation. In this case, Tau Cygna would be the 19th brightest star in its constellation.

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