BALTIMORE – Darth Vader proclaiming he’s Luke Skywalker’s father, John Travolta preening in his underwear and an early 20th-century deaf activist communicating in sign language are among the images that will be preserved by the Library of Congress as part of its National Film Registry.

The 25 films selected this year include “The Empire Strikes Back,” the 1980 sequel to “Star Wars” that many critics and fans consider the best of George Lucas’ six “Star Wars” films.

While Lucas didn’t direct “Empire” — he entrusted it to the late Irvin Kershner — he got another film selected for the registry: his student short “Electronic Labyrinth: THX 1138 4EB.” Lucas’ “Star Wars” and “American Graffiti” are already among the 550 titles in the registry.

The Library of Congress announced the selections last week. The goal of the registry, which began in 1989, isn’t to identify the best movies ever made, but to preserve films with artistic, cultural or historical significance.

Librarian of Congress James H. Billington has chosen each of the films in the registry, culling them from suggestions by the National Film Preservation Board and the public. More than 2,100 films were nominated by the public in 2010.

Original copies of films picked for the registry are kept safe and available for viewing by future generations.

This year’s selections also include “Saturday Night Fever,” the 1977 disco musical starring Travolta; “Preservation of the Sign Language,” a two-minute film made in 1913; “Airplane!” the 1980 disaster-film spoof; and “The Pink Panther” (1964).