Harry Styles, Tulisa, Jean Dujardin: Celebrity pictures February 15

Today's celebrity pictures include One Direction's Harry Styles and a coy Nick Grimshaw at The Groucho Club with presenter Alexa Chung, X Factor runner-up Rebecca Ferguson dines at The Ivy, and Tim Burton and Helena Bonham Carter enjoy a romantic Valentine's date at The Delauney.

Meanwhile, actor Dan Ackroyd signs bottles of Crystal Head Vodka in London's Soho, and recent BAFTA winner Jean Dujardin and wife Alexandra Lemmy attend their Les Infideles premiere in Paris.

In Los Angeles, a summery Tulisa Contostavlos heads to a recording studio, Matt Groening is joined by The Simpsons cast as the cartoon creator receives his star on the Hollywood Walk of Fame, and Jessica Alba treats herself to a manicure and massage.

And in New York, 19-year-old model Kate Upton attends the launch of Sports Illustrated's 2012 Swimsuit Issue on which she graces the cover.