Star Weed?

I don't know what this is. It grows along one edge of my vegi garden but its nothing we've planted. Its viney and wants to wrap around my tomotoes. It must be a weed but its a pretty one.

Brrrrrrrrr

I'm quite sure this is the hottest day in history. Well at least for this summer. Its too hot to go outside to see how hot it is. I'm so tired of this hot hot weather. Hopefully this shot will cool us all down a little. Can you feel that cold breeze blowing off the snow?.