A person interested in the estate or funds affected by the decree or order, who was not a party to the special proceeding in which it was made, but who was entitled by law to be heard therein, upon his application, or who has acquired, since the decree or order was made, a right or interest which would have entitled him to be heard, if it had been previously acquired, may move to reopen the judgment within thirty (30) days from the date of the decree or order. The facts which entitle such person to vacate the judgment must be shown by an affidavit which must be filed with the motion to vacate.