'Big Bang Theory' Cast Emotionally Celebrates Series Finale With Touching Tributes and Throwback Pics

The main stars of the long-running sitcom commemorated the end of an era with heartfelt posts on Instagram.

After 12 seasons, viewers bid a tearful farewell to The Big Bang Theory on Thursday as the acclaimed show aired it's touching series finale.

However, fans of the long-running sitcom weren't the only ones caught up in the emotion of saying goodbye and celebrating the end of an era. The Big Bang Theory's central stars -- who've worked side by side for over a decade -- also took to social media to pay tribute to their time together and share some sweet memories.

Kaley Cuoco took to Instagram on Thursday, shortly before the final kicked off, to share a behind-the-scenes snapshot from the day they taped the last scene of the last episode, and everyone who worked on the show came together to the special occasion.

"One of my favourite BTS pictures from tonight’s finale taping," Cuoco wrote in the caption. "Entire cast, writers and crew, huddling together to watch the final scene."

After the episode concluded, Cucoo shared a group shot of her and her fellow co-stars alongside Stephen Colbert at a taping of Thursday night's Late Show.

"And that’s all folks!!" Cuoco wrote. "It’s now feeling truly real ? I love this group so so much."

Johnny Galecki also shared a heartwarming glimpse behind the scenes of the finale's production, where creator Chuck Lorre worked the clapper himself to commemorate the final scene they'd ever shoot.

"The incomparable #chucklorre on clapboard for the final take of the final live scene of the final episode," Galecki captioned the touching clip.

Jim Parsons commemorated the bittersweet evening with a snapshot of the cast's group hug after wrapping production on the series finale.

"It was really hard to pick the right pic for this post, so here is a shot of us in a hug after we filmed the last group scene we would ever film for the series," Parsons explained. "I hope you get a chance to tune in and i hope you enjoy all of it."

"If you enjoy it even half as much as we’ve enjoyed (LOVED) creating this show for the past 12 years, then that’ll be a WHOLE WHOLE lot of enjoyment," he added. "All of us will miss seeing you in this format, but we will be around in all sorts of ways, I assure you... love love love."

Meanwhile, before the show kicked off, Mayim Bialik shared a slideshow of on-set photos, showing her with her co-stars and the show's writers and crew during production.

The actress captioned the heartfelt series of beaming snapshots simply, "Oy. The emotions."

Bialik also took to Instagram Thursday morning to share a pic of the final draft of the finale's script, writing, "Tonight's the night! Excited for everyone to see this moving, funny, beautiful finale."

Melissa Rauch also took a walk down memory lane as she shared a slew of throwback photos, including two from her very first day on set when she joined the cast in Season 3.

"Every heart expanding adventure begins with a single step. This was mine for @bigbangtheory_cbs," Rauch wrote. "My first episode. Or my first 'step-isode' - if you will. The second pic is shortly after I joined the cast (I couldn’t believe I had my very own dressing room)! The friendships and memories that would build from these moments simply overwhelm me."

"It’s not that I can’t stop/won’t stop...I can technically stop, but making a conscious decision not to at this moment," Rauch captioned another flashback pic, among a series of touching posts. "MORE MEMORIES HOLLAAAAAAA!!!"

Finally, Kunal Nayyar seemed to emotionally sum up the true grandness of the occasion with a video showing the empty audience seats and silent, vacant set while he quietly sang the last words of the show's famous theme song.

Nayyar captioned the clip with a simple and elegant, "Goodbye…"

For more on The Big Bang Theory's long, celebrated legacy, check out the video below.