code: def coneSearch(self, center, radius=3*u.arcmin, magnitudelimit=20):
          '''
          Run a cone search of the Gaia DR2.
          '''
  
  
          self.magnitudelimit = magnitudelimit
  
          # define a query for cone search surrounding this center
          conequery = .format(center.ra.deg, center.dec.deg, radius.to(u.deg).value, magnitudelimit)
  
  
          # run the query
          self.speak('querying 2MASS, centered on {} with radius {}, for J<{}'.format(center, radius, magnitudelimit))
          table = self.query(conequery)
  
  
  
  
          # create skycoord objects
          self.coordinates = coord.SkyCoord(  ra=table['ra'].data*u.deg,
                                          dec=table['dec'].data*u.deg,
                                          obstime=Time(table['j_date'].data, format='jd'))
  
          self.magnitudes = dict(         J=table['j_m'].data,
                                          H=table['h_m'].data,
                                          Ks=table['ks_m'].data)
          self.magnitude = self.magnitudes['J']
docs: Run a cone search of the Gaia DR2.