Meester shakes and shimmies her way into the Metropolitan Opera in New York. Plus: Mariah Carey, Gwyneth & Robert Downey, Jr., Patrick Dempsey and more

YELLOW FEVER

Her show Gossip Girl returned Monday, but Leighton Meester wasn't staying home to watch it. Instead, the actress makes a dramatic entrance at opening night of La Fille Du Régiment at the Metropolitan Opera in New York.

Hooked on Gossip Girl? Test your knowledge of the show with our quiz.