// cpt-city: pd/astro/aurora_borealis (cpt)
//
// Gradients from photographs
//
// author: Piecrust Design
// copyright: Public domain
// year: 2007
// url: https://phillips.shef.ac.uk/pub/cpt-city/pd/astro
#declare aurora_borealis =
color_map {
  [0.00000 color rgbf <0.3451,0.1922,0.3294,0.0000>]
  [0.02080 color rgbf <0.3608,0.2000,0.3373,0.0000>]
  [0.04170 color rgbf <0.3765,0.2078,0.3451,0.0000>]
  [0.06250 color rgbf <0.3843,0.2118,0.3529,0.0000>]
  [0.08330 color rgbf <0.3922,0.2118,0.3569,0.0000>]
  [0.10420 color rgbf <0.4078,0.2235,0.3686,0.0000>]
  [0.12500 color rgbf <0.4235,0.2314,0.3804,0.0000>]
  [0.14580 color rgbf <0.4353,0.2392,0.3843,0.0000>]
  [0.16670 color rgbf <0.4510,0.2431,0.3922,0.0000>]
  [0.18750 color rgbf <0.4667,0.2471,0.4000,0.0000>]
  [0.20830 color rgbf <0.4824,0.2510,0.4078,0.0000>]
  [0.22920 color rgbf <0.5020,0.2667,0.4157,0.0000>]
  [0.25000 color rgbf <0.5176,0.2824,0.4275,0.0000>]
  [0.27080 color rgbf <0.5294,0.2863,0.4314,0.0000>]
  [0.29170 color rgbf <0.5373,0.2863,0.4314,0.0000>]
  [0.31250 color rgbf <0.5529,0.2863,0.4314,0.0000>]
  [0.33330 color rgbf <0.5686,0.2863,0.4314,0.0000>]
  [0.35420 color rgbf <0.5961,0.3059,0.4549,0.0000>]
  [0.37500 color rgbf <0.6235,0.3255,0.4784,0.0000>]
  [0.39580 color rgbf <0.6353,0.3216,0.4706,0.0000>]
  [0.41670 color rgbf <0.6471,0.3176,0.4667,0.0000>]
  [0.43750 color rgbf <0.6627,0.3294,0.4706,0.0000>]
  [0.45830 color rgbf <0.6784,0.3373,0.4784,0.0000>]
  [0.47920 color rgbf <0.6902,0.3373,0.4745,0.0000>]
  [0.50000 color rgbf <0.7020,0.3373,0.4706,0.0000>]
  [0.52080 color rgbf <0.7176,0.3490,0.4784,0.0000>]
  [0.54170 color rgbf <0.7294,0.3569,0.4902,0.0000>]
  [0.56250 color rgbf <0.7529,0.3725,0.4980,0.0000>]
  [0.58330 color rgbf <0.7765,0.3882,0.5059,0.0000>]
  [0.60420 color rgbf <0.7882,0.4157,0.5176,0.0000>]
  [0.62500 color rgbf <0.8000,0.4392,0.5333,0.0000>]
  [0.64580 color rgbf <0.8118,0.4706,0.5451,0.0000>]
  [0.66670 color rgbf <0.8235,0.5059,0.5608,0.0000>]
  [0.68750 color rgbf <0.8235,0.5490,0.5765,0.0000>]
  [0.70830 color rgbf <0.8275,0.5961,0.5961,0.0000>]
  [0.72920 color rgbf <0.8157,0.6549,0.5922,0.0000>]
  [0.75000 color rgbf <0.8000,0.7176,0.5882,0.0000>]
  [0.77080 color rgbf <0.7725,0.7765,0.5725,0.0000>]
  [0.79170 color rgbf <0.7451,0.8314,0.5569,0.0000>]
  [0.81250 color rgbf <0.6980,0.8627,0.5333,0.0000>]
  [0.83330 color rgbf <0.6549,0.8902,0.5137,0.0000>]
  [0.85420 color rgbf <0.6196,0.9020,0.4863,0.0000>]
  [0.87500 color rgbf <0.5882,0.9137,0.4588,0.0000>]
  [0.89580 color rgbf <0.5373,0.8863,0.4235,0.0000>]
  [0.91670 color rgbf <0.4863,0.8588,0.3882,0.0000>]
  [0.93750 color rgbf <0.4549,0.7098,0.3882,0.0000>]
  [0.95830 color rgbf <0.4196,0.5608,0.3922,0.0000>]
  [0.97920 color rgbf <0.4078,0.4627,0.4000,0.0000>]
  [1.00000 color rgbf <0.3961,0.3686,0.4039,0.0000>]
}