Leonard Nimoy, known best for his role as Mr. Spock in the long-running TV series “Star Trek,” died Friday at his home in Los Angeles, the New York Times reported. He was 83. His widow, Susan Bay Nimoy, said the cause of death was end-stage chronic obstructive pulmonary disease, which the actor himself said he developed after years of cigarette smoking.

Nimoy helped bring science fiction to the mainstream with his "Star Trek" portrayal as the logical and stoic science officer Spock, who was often the voice of reason on the starship Enterprise. He was loved by science fiction fans long after the series ended in 1969 for his frequent cameos in other science fiction shows and his strong fan engagement. Nimoy also directed what is widely considered one of the best "Star Trek" feature films, "Star Trek IV: The Voyage Home." He was known for his other artistic pursuits, which included photography, poetry, songwriting and stage acting.

Nimoy was hospitalized earlier this month due to complications with the lung disease and appealed to fans to stop smoking. Fans and his former "Star Trek" co-stars George Takei and William Shatner, who played Mr. Sulu and Capt. James T. Kirk, respectively, expressed their condolences across social media.