In 2293, the Helin was assigned a Neutral Zone patrol mission in Sector 21290. The ship was named on a Starship Mission Assignments chart on the USS Enterprise-A bridge. (Star Trek VI: The Undiscovered Country)
This ship was not mentioned in the movie's dialogue, but was listed in several starship status charts seen on the sets of the film.
In an issue of Bjo Trimble's Space-Time Continuum, it was mentioned that American astronomer Eleanor F. Helin was given a model of an Oberth-class ship which bore this name. The Palomar Observatory website has a picture of a dedication plaque for the ship, also stating that it was given to Helin "by the Star Trek franchise". It is unclear if a ship model was indeed given as well, or if the reference to a model in Space-Time Continuum is erroneous.