Together, they are one of fashion’s most famous bosom buddies.

One is a super fit, superhuman A-lister, with a wardrobe to die for. The other, a sought-after designer, famed for her pared-back yet feminine aesthetic and roll call of celebrity clients. Now, Gwyneth Paltrow and are to team up for a mystery Goop.com collaboration.

On Gwyneth’s lifestyle website today, ELLE spotted a banner alluding to the partnership: “Stella McCartney X Goop launching September ‘13”.

What could it be?

The timing of the collaboration would suggest that it’s fashion related - a fitness clothing range perhaps? Tracy Anderson-honed Gwyneth is no stranger to punishing fitness regimes, while Stella has proven she can cut it in sportswear, thanks to her Adidas collaborations and official London 2012 Olympics kit.

As both stars are vegans, how about a line of vegan-friendly Stella McCartney accessories? Or, maybe the stylish London mums plan to dress the Harper Beckhams of this world with a luxury childrens clothing capsule collection.

The possibilities are endless.

What do you think the collaboration could be? Let us know!

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