According to the Star Trek: Star Charts (pg. 64, "United Federation of Planets I"), the Kessik system was located in or near Federation space, and was one of the three points of the Delta Triangle. Primary was a Class G star with a magnitude of +1, which was a hundred times brighter than Sol. Kessik IV, and its sister planet Kessik III, were listed as member planets of the Federation in 2378.
In the Star Trek Online episode "A Gathering Darkness", the Undine destroy this planet after it is completely assimilated by the Borg.