Expert: Courtney Seligman - 1/12/2009

Question
what caused the sun to become tilted at 7.25 degrees?

Answer
The Sun's rotation is presumably the average of the net rotation of the material that fell into it during its formation. By and large, that should be about the same as the net rotation of the Solar System, so the difference between the Sun's rotational axis, and the average rotational axis of the Solar System, should be small. But I doubt that anyone thinks the few degrees difference between the two is large enough to be at all surprising, and haven't seen any discussion of whether it should be any smaller, or larger.

Courtney Seligman

Btw, the 7.25 degree tilt is relative to our orbit, and since our orbit is tilted slightly relative to the average orbital plane of the Solar System, the Sun's tilt relative to that may be a degree or two smaller; but I'd have to do some research, to verify that.