Multiple realities(covers information from several alternate timelines)
Alpha Ataru was a location.
In 2367, Alpha Ataru's position 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, Alpha Ataru's position was labeled on a tactical situation monitor in the ready room aboard the USS Enterprise-D. (TNG: "Yesterday's Enterprise" okudagram)
This location was only mentioned in writing.