'Specifies the type of coordinate system.  Valid choices are:
\'eq_FK4\', \'eq_FK5\', \'ICRS\', \'ecl_FK4\', \'ecl_FK5\', \'galactic\',
\'supergalactic\', \'xy\', \'barycentric\', or \'geo_app\''

@property
def system(self):

    return self._system
