The Terlina system was a remote planetary system.

After the destruction of the Omicron Theta colony in 2338, Dr. Noonian Soong and his wife Juliana re-settled on Terlina III.

In 2367, Data brought the USS Enterprise-D to this system in response to Dr. Soong's summoning signal. Lore also arrived at the system aboard a small Pakled vessel. (TNG: "Brothers", "Inheritance")

According to the script, the pronunciation for Terlina is "tur-LEE-nah". [1]
The identity of Soong's star system was not revealed until TNG: "Inheritance".