docs: def d(self):
          """ Note this should work from child parents as .d propergates, calculates using the star estimation method
          estimateDistance and estimateAbsoluteMagnitude
          """
          # TODO this will only work from a star or below. good thing?
          d = self.parent.d
          if ed_params.estimateMissingValues:
              if d is np.nan:
                  d = self.estimateDistance()
                  if d is not np.nan:
                      self.flags.addFlag('Estimated Distance')
              return d
          else:
              return np.nan