What better place to celebrate the first day of summer than at the beach? Jennifer Aniston did just that on June 21, gracefully jogging near Chicago's North Avenue Beach as she filmed one of her first scenes for the romantic comedy The Break Up. She's been soaking in the sunny atmosphere ever since arriving in the Windy City with her dog Norman. (Also keeping her company for the shoot: hairstylist pal Chris McMillan, who trimmed her soon-to-be ex-husband Brad Pitt's locks June 16 before leaving L.A.) Emerging from her trailer after the beach shoot, Aniston greeted a gaggle of cheering fans, who were impressed by her upbeat demeanor in the wake of the Brangelina brouhaha. "She has a glow to her," says Brandon Fitzgerald, 13, whose mom, Deanna, marveled over Aniston's svelte figure (she has been spending time on her hotel's treadmill). "Lucky next guy," says Deanna. "Too bad for Brad!"

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