[Class] DATABASE [Condition] 
Cannot change the owner of system databases master, model, tempdb, the resource database, or a database that is used as a distribution database. The principal must be a login. If the principal is a Windows login without a corresponding SQL Server login, the principal must have CONTROL SERVER permission and TAKE OWNERSHIP permission on the database. If the principal is a SQL Server login, the principal cannot be mapped to a certificate or asymmetric key. Dependent aliases will be mapped to the new database owner. The DBO SID will be updated in both the current database and in sys.databases.