Star Tracks: Wednesday, October 12, 2011

Birthday boy Hugh Jackman (he turns 43 on October 12) readies himself for a muscle-building workout Tuesday in New York City, just days after topping the box office with Real Steel.

After returning to the set of Mad Men, January Jones basks in her mommy glow with newborn son Xander Dane in Los Angeles on Tuesday.

Watch your step! Matthew McConaughey walks with caution while

disembarking from a boat with partner Camila Alves Tuesday on the Tampa,

Fla., set of his latest flick, Magic Mike.

Kate Hudson gets wiggy with it on the set of her new movie, The Reluctant Fundamentalist, outside New York's Metropolitan Museum of Art on Tuesday.

He's like a fine wine! Johnny Depp – who has a tattoo reading "wino forever" – samples some red Tuesday, while perusing the works of artists Jordi Molla and Domingo Zapata at an exhibition held at West Hollywood's Chateau Marmont.

A bespectacled Matthew Broderick goes eye-to-eye with Tonk, a horse from Whitefish, Mont., who charged a grizzly bear in order to save an eight-year-old boy, during a visit to the Late Show with David Letterman Tuesday in N.Y.C.

A beaming Betty White has a little fun with George Clooney's faux Time magazine cover while celebrating the premiere of British singer Luciana's music video, "I'm Still Hot" – which features the Emmy-winning actress – in West Hollywood on Tuesday.

Mary-Kate and Ashley Olsen stick together during the Martha Marcy May Marlene afterparty (which stars little sister Elizabeth), at New York's Empire Hotel Tuesday night.

After launching her latest collection in New Orleans, a solo Jessica Simpson continues to fuel pregnancy rumors as she makes her way through LAX on Monday.

First Lady Michelle Obama gets her heart racing with a few jumping jacks alongside local school children on the South Lawn of the White House in Washington, D.C., on Tuesday. The event, part of the her Let's Move! Campaign, aimed to break the Guinness World Records title for the most people doing jumping jacks in a 24-hour period.

After spending the weekend camping with wife Demi Moore, Ashton Kutcher makes a low-key java run Tuesday in Los Angeles.

Hands-on mom Sarah Jessica Parker sneaks in some extra twin time with 2-year-old daughters Tabitha (left) and Loretta on Tuesday in New York City.

Esquire magazine's 2011 Sexiest Woman Alive, Rihanna, steps out of her Glasgow hotel Tuesday in a weather-friendly layered look with biker boots and shades.

Thanks for Sharing star Gwyneth Paltrow shows off her cycling skills – and helmet safety! – while riding through the film's New York City set Tuesday.

What a smile! Heidi Klum gets into the spirit of the season Tuesday, playing with pumpkins during a photo shoot at Mr. Bones Pumpkin Patch in Beverly Hills.