What to Watch on Thursday: ‘Big Bang Theory’ and ‘Young Sheldon’ universes collide

Tam (Robert Wu, left) and Sheldon Cooper (Jim Parsons) in CBS’ ”Big Bang Theory.”
Tam (Robert Wu, left) and Sheldon Cooper (Jim Parsons) in CBS’ ”Big Bang Theory.” CBS Broadcasting, Inc.

Big Bang Theory (8 p.m., CBS) - Viewers of “Young Sheldon” will especially appreciate tonight’s “Big Bang,” which pulls Sheldon’s childhood best friend Tam into the BBT universe. When Sheldon won’t tell anyone why he’s never mentioned Tam, Leonard takes matters into his own hands and tracks him down. Tonight’s “Young Sheldon” airs at 8:30 and features Sheldon’s first sleepover at Tam’s house.

Supernatural (8 p.m., The CW) - Sam enlists everyone’s help in trying to track down Dean in the Season 14 premiere.

The Good Place (8:30 p.m., NBC) - Sequestered on earth, Michael and Janet continue to meddle in the lives of Eleanor, Chidi, Tahani and Jason to remove any obstacles that will derail their efforts to become better people.

Murphy Brown (9:30 p.m., CBS) - After Murphy attends a sexual harassment seminar for the “Murphy in the Morning” staff, she finds herself reeling from a long-repressed memory (please don’t let it be Stan Lansing).

The Return of the Shelby Swamp Man (10 p.m., History) — This new series follows Shelby Stanga, known as the Swamp Man. Shelby, recognized by viewers of “Ax Men,” moves deeper into the Louisiana Bayou when his houseboat is destroyed by a hurricane.

Some programming details are provided by networks.