Tigan-7 was a planet, the home to the Tigan race. The planet had a great reserve of geothermic energy, which the Tigan use to power the containment field of the gravimatrix, their black hole based power facility.
Tigan was visited by the USS Enterprise-D on stardate 41590.8, at which point Enterprise personal uncovered a global conspiracy which had been repeatedly rewriting Tigan history using the Tigan's interface technology. (TNG comic: "History Lesson")
- In the original references in "History Lesson" the planet was only ever referred to as Tigan. However in the blurb released for the issue prior to publication it was referred to as Tigan-7, the addition of the numeral was confirmed in-universe when the planet was referenced in "Space Seeds".