We had a contract to purchase a home contract was signed by power of attorney owner died the power of attorney is also the executor of the will how long will it take for us to close on this house?

Punctuation would have been a real blessing in figuring out your question. And a power of attorney is a piece of paper, not a person. The person who holds the POA is called an "attorney in fact".

Anyway, with that out of the way, it depends. Has the will been admitted to probate? What does it say about closing in the contract to purchase?

A POA ends at the death of the grantor. So having a POA does not empower someone to sell the property. However, the duly appointed executor DOES have that power. So you want to make sure the person can prove they are the executor. Probate courts records should be sufficient.

As to how long it will take, that's dependent on the status of the estate and probate court. It will also depend on whether you have the financing lined up and can schedule the closing. Have you discussed this with the executor?