Jim Parsons as Sheldon Cooper on ‘The Big Bang Theory’ (Screenshot via YouTube)

“The Big Bang Theory” will end in May 2019 after 12 seasons, CBS and Warner Bros announced on Wednesday. The series’ conclusion is due to star Jim Parsons’ decision to leave the show, according to Entertainment Weekly.

CBS was reportedly in negotiations with the cast, including fellow stars Kaley Cuoco, Johnny Galecki, Kunal Nayyar, Mayim Bialik, Melissa Rauch and Simon Helberg, for two more seasons. However, Parsons wasn’t interested in continuing work on the show. Although the series features many characters, Parsons role as Sheldon Cooper is the core of many storylines.

Parsons, who won four Emmys and one Golden Globe award for his role as Sheldon, bid farewell to the series in a lengthy Instagram post. He did not mention his involvement in the show’s conclusion.

“It is hard (nearly impossible, actually) to really accepot that this picture of the first of the final 24 episodes we will shoot for The Big Bang Theory,” he wrote accompanying an image of the principle cast,” he writes.  “I am so terribly grateful for the cast in this picture and the cast members who aren’t pictured here- whether they were in one scene or many episodes along the way; you are all my playmates that I have fallen in love with.”

❤️Swipe for my caption to this picture which was too long to just write here (not surprising given the circumstances) ❤️

A post shared by Jim Parsons (@therealjimparsons) on Aug 23, 2018 at 9:31am PDT

Parsons’ co-stars Bialik and Cuoco also expressed their sadness to see the show end.

“Am I happy? Of course not. This has been my job since Melissa Rauch and I joined the cast as regulars in season four,” Bialik wrote on her blog. “This is hard. I love coming to work and pretending to be Amy. She’s a riot. She’s me, and I am her. And soon she will not be mine to create. It’s very sad. I fear it’s going to be very hard to not cry every day for the next 23 episodes! But, as a cast, we love bringing joy to our viewers and we will continue to do that to the best of our collective ability.”

Cuoco penned an emotional Instagram post writing, “This ride has been a dream come true and as life changing as it gets. No matter when it was going to end , my heart would have always been broken in two. Drowning in tears, we promise to bring you the best season yet.”

This ride has been a dream come true and as life changing as it gets. No matter when it was going to end , my heart would have always been broken in two. Drowning in tears, we promise to bring you the best season yet. To the fans, our crew, families, Chuck Lorre, Warner Brothers , CBS, and everyone who has supported us for so many years, thank you. We are goin out with a bang ? @bigbangtheory_cbs

A post shared by @ normancook on Aug 22, 2018 at 1:27pm PDT

“The Big Theory” is CBS’ number one comedy. It will also be the longest-running multi-camera series in television history with its conclusion of 12 seasons and 279 episodes.