Celebrity Pictures: Robert Pattinson, Rihanna, Charlie Sheen

Today's celebrity pictures include a casual Robert Pattinson wearing his cap back-to-front as he attends a TimesTalks Presents event to promote new movie Cosmopolis in New York.

Also in the Big Apple, Kelly Osbourne, 30 Rock's Tracy Morgan and fiancée Megan Wollover, and Sports Illustrated model Kate Upton attend the Samsung Galaxy Note 10.2 launch.

In Los Angeles, a stylish Rachel Bilson pops out for coffee, Heidi Klum wears an ill-fitting leopard-print dress to unveil her children's clothing collection 'Truly Scrumptious' for Babies R Us, and glamorous Vampire Diaries star Nina Dobrev leaves the W Hotel.

Meanwhile, Charlie Sheen hops out of his SUV smoking a cigarette in Toronto, and Rihanna arrives at Narita International Airport ahead of her performance at Summer Sonic 2012 Festival in Tokyo.