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

        Parameters
        ----------
        center : SkyCoord object, or str
            The center around which the query will be made.
            If a str, SkyCoord will be resolved with coord.SkyCoord.from_name
        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=20,
                  **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, or str
            The center around which the query will be made.
            If a str, SkyCoord will be resolved with coord.SkyCoord.from_name
        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.)
        '''

        center = parse_center(center)

        # define a query for cone search surrounding this center
        conequery = """{} WHERE CONTAINS(POINT('ICRS',gaiadr2.gaia_source.ra,gaiadr2.gaia_source.dec),CIRCLE('ICRS',{},{},{}))=1 and phot_g_mean_mag < {}""".format(cls.basequery, center.ra.deg, center.dec.deg, radius.to(u.deg).value, magnitudelimit)
        print(conequery)

        # run the query
        print('querying Gaia DR2, centered on {} with radius {}, for G<{}'.format(center, radius, magnitudelimit))
        table = query(conequery)

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