How long is probate in your state and does a domestic partner have any rights to my sons estate since their was no will?

Probate in CA usually lasts between 9 and 18 months but sometimes longer. If there was no will then the domestic partner cannot be an executor. An executor must be named in a will. He can however be made the Personal Representative of the Estate-with duties similar to an executor.

As a domestic partner he would have first priority under the probate code to act as the Personal Representative. All the community property would go to the domestic partner. If there was any separate property then you might be entitled to 1/2 interest in that separate property assuming your son had no children.