Bob Newhart to appear on 'The Big Bang Theory'

A comedy legend is headed to “The Big Bang Theory.”

Bob Newhart (“Bob Newhart Show,” “Newhart”) will play Professor Proton, the former host of Sheldon’s favorite science show. The Professor actually was a key player in Sheldon (played by Jim Parsons) and Leonard’ (played by Johnny Galecki) childhoods.

Newhart is first scheduled to appear May 2, as Sheldon finds him online, and hires the Professor to come over to their apartment.

Also appearing during this sixth season are Regina King (“Southland”), Meagan Fay (“Roseanne”), LeVar Burton (“Star Trek”), astronaut Buzz Aldrin and Ryan Cartwright (“Bones”). Kate Micucci (“Raising Hope”) will recur as Raj’s (played by Kunal Nayyar) next love interest, Lucy.

A seventh season has already been renewed. “The Big Bang Theory” also stars Kaley Cuoco, Simon Helberg and Mayim Bialik, and focuses on a group of smart guys whose horizons are broadened when they meet a pretty girl.

Newhart is recent years has appeared on NBC’s “ER” (which he received an Emmy nomination for), Lifetime’s anthology “Five,” CBS’ “NCIS” and “Desperate Housewives.” He has also appeared in recent films “Elf” with Will Ferrell and “Horrible Bosses” in 2011.

Newhart is represented by Innovative Artists and Monarch Entertainment Group.