code: def sun_earth_distance_correction(utc_time):
      
      year = 365.256363004
      # This is computed from
      # http://curious.astro.cornell.edu/question.php?number=582
      # AU = 149597870700.0
      # a = 149598261000.0
      # theta = (jdays2000(utc_time) - 2) * (2 * np.pi) / year
      # e = 0.01671123
      # r = a*(1-e*e)/(1+e * np.cos(theta))
      # corr_me = (r / AU) ** 2
  
      # from known software.
      corr = 1 - 0.0334 * np.cos(2 * np.pi * (jdays2000(utc_time) - 2) / year)
  
      return corr
docs: Calculate the sun earth distance correction, relative to 1 AU.