AT: "at"
Carson was an astronomical object.
In 2367, the location of Carson was labeled on a tactical situation monitor in Captain Benjamin Maxwell's ready room on the USS Phoenix. (TNG: "The Wounded", okudagram)
In 2366, in an alternate timeline, during the Federation-Klingon War, the location of Carson was labeled on a tactical situation monitor in the ready room aboard the USS Enterprise-D (TNG: "Yesterday's Enterprise", okudagram)