add dm.dfs_rc_auto() to download rc automatically

        except:

            return False

    def get_coord(self):

        """ Get pointing coordinate. """

        header = fits.getheader(self.l0_detector(detector=self.target_detectors[0]))

        pointing_ra = header["RA_OBJ"]

        pointing_dec = header["DEC_OBJ"]

        return pointing_ra, pointing_dec

    def dfs_rc_auto(self):

        """ Download RC. """

        assert self.dfs_is_available()

        assert len(self.target_detectors) >= 1

        pointing_ra, pointing_dec = self.get_coord()

        refcat = self.dfs_rc_query(

            ra=pointing_ra,

            dec=pointing_dec,

            columns=(

                    'ref_epoch',

                    'ra',

                    'ra_error',

                    'dec',

                    'dec_error',

                    'parallax',

                    'parallax_error',

                    'pmra',

                    'pmra_error',

                    'pmdec',

                    'pmdec_error',

                    'phot_g_mean_mag',

                    'source_id'

            ),

            radius=2,

            min_mag=0,

            max_mag=30,

            obstime=-1,

            limit=-1

        )

        print(

            f"RA, Dec = [{pointing_ra}, {pointing_dec}], "

            f"Status = {isinstance(refcat, Table)}, "

            f"N_entries = {len(refcat)}"

        )

        return refcat

    def dfs_rc_query(

            self,

            ra=180,