Create a Constellation from a cone search of the sky,
        characterized by a positional center and a radius from it.

        Parameters
        ----------
        center : SkyCoord object
            The center around which the query will be made.
        radius : float, with units of angle
            The angular radius for the query.
        magnitudelimit : float
            The maximum magnitude to include in the download.
            (This is explicitly thinking UV/optical/IR, would
            need to change to flux to be able to include other
            wavelengths.)

def from_cone(cls, center,
                  radius=3*u.arcmin,
                  magnitudelimit=None,
                  **kw):
        '''
        Create a Constellation from a cone search of the sky,
        characterized by a positional center and a radius from it.

        Parameters
        ----------
        center : SkyCoord object
            The center around which the query will be made.
        radius : float, with units of angle
            The angular radius for the query.
        magnitudelimit : float
            The maximum magnitude to include in the download.
            (This is explicitly thinking UV/optical/IR, would
            need to change to flux to be able to include other
            wavelengths.)
        '''

        # make sure the center is a SkyCoord
        center = parse_center(center)

        criteria = {}
        if magnitudelimit is not None:
            criteria[cls.defaultfilter + 'mag'] = '<{}'.format(magnitudelimit)

        v = Vizier(columns=cls.columns,
                   column_filters=criteria)
        v.ROW_LIMIT = -1

        # run the query
        print('querying Vizier for {}, centered on {} with radius {}, for G<{}'.format(cls.name, center, radius, magnitudelimit))

        table = v.query_region(coordinates=center,
                               radius=radius,
                               catalog=cls.catalog)[0]

        # store the search parameters in this object
        c = cls(cls.standardize_table(table))
        c.standardized.meta['catalog'] = cls.catalog
        c.standardized.meta['center'] = center
        c.standardized.meta['radius'] = radius
        c.standardized.meta['magnitudelimit'] = magnitudelimit
        #c.center = center
        #c.radius = radius
        #c.magnitudelimit = magnitudelimit or cls.magnitudelimit
        return c