Here's how "The Big Bang Theory" honored Leonard Nimoy

If you watch "The Big Bang Theory," you'll know the CBS hit series regularly references "Star Trek" actor Leonard Nimoy.

Lead character Sheldon (Jim Parsons) is obsessed with Nimoy. On one episode, Penny (Kaley Cuoco) gave Sheldon a used napkin signed by the actor.

Nimoy even guest-starred in a season 5 episode, voicing a tiny action-figure Spock.

After the actor passed away February 27, Thursday's episode of "The Big Bang Theory" paid tribute to the actor, ending on a portrait of Nimoy with the caption "The impact you had on our show and our lives is everlasting." 

Here's how it appeared on screen:

CBS

The show's social media accounts followed suit with Sheldon giving the "Star Trek" Vulcan salute that Nimoy popularized on the series.