docs: def ratioTerminatorToStar(H_p, R_p, R_s):  # TODO add into planet class
      r"""Calculates the ratio of the terminator to the star assuming 5 scale
      heights large. If you dont know all of the input try
      :py:func:`calcRatioTerminatorToStar`
  
      .. math::
          \Delta F = \frac{10 H R_p + 25 H^2}{R_\star^2}
  
      Where :math:`\Delta F` is the ration of the terminator to the star,
      H scale height planet atmosphere, :math:`R_p` radius of the planet,
      :math:`R_s` radius of the star
  
      :param H_p:
      :param R_p:
      :param R_s:
      :return: ratio of the terminator to the star
      """
  
      deltaF = ((10 * H_p * R_p) + (25 * H_p**2)) / (R_s**2)
      return deltaF.simplified