docs: def SNRPlanet(SNRStar, starPlanetFlux, Nobs, pixPerbin, NVisits=1):
      r""" Calculate the Signal to Noise Ratio of the planet atmosphere
  
      .. math::
          \text{SNR}_\text{planet} = \text{SNR}_\text{star} \times \Delta F \times
          \sqrt{N_\text{obs}}
          \times \sqrt{N_\text{pixPerbin}} \times \sqrt{N_\text{visits}}
  
      Where :math:`\text{SNR}_\star` SNR of the star detection, :math:`\Delta F`
      ratio of the terminator to the star, :math:`N_\text{obs}` number of
      exposures per visit, :math:`N_\text{pixPerBin}` number of pixels per
      wavelength bin, :math:`N_\text{visits}` number of visits.
  
      :return:
      """
  
      SNRplanet = SNRStar * starPlanetFlux * \
          sqrt(Nobs) * sqrt(pixPerbin) * sqrt(NVisits)
  
      return SNRplanet