The Surya-class frigate was a type of starship on active duty in the Federation Starfleet during the mid- to late-23rd century. It was the precursor to the Avenger-class heavy frigates. (Ships of the Star Fleet, vol. 1 [revised]) The Anton-class research cruisers (FASA RPG: Federation Ship Recognition Manual) may be this class's nomenclature in an alternate timeline. The USS Argus (NCC-1888) was a ship of this class. (Star Trek: The Adventures of Argus) USS Avenger was a ship of this class until the refit of 2272-75. (Star Trek: Avenger)