Leonard Nimoy, who famously played Mr. Spock, died at home Friday morning in Bel Air... after battling chronic obstructive pulmonary disease.
The "Star Trek" star announced last year that he was battling the disease and atrributed it to years and years of smoking. He had given up the habit 30 years ago.
TMZ broke the story ... Nimoy checked into UCLA Medical Center last week for intense chest pains -- but was eventually released.
Nimoy started playing Mr. Spock when the TV show debuted in 1966 ... and is the only actor to appear in every episode of that original series. He continued in the Spock role through most of the movies -- including the most recent reboot in 2013.
Aside from acting ... he also wrote books of poetry, 2 autobiographies ... and even recorded albums of cover songs.
Nimoy tweeted for the last time on Feb. 22, saying ... "A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP"
He was 83.