This is a 15 minute exposure of star trails above one of the main pools at Bosque del Apache National Wildlife Refuge in New Mexico. I took this when it first looked fully dark outside and I was still able to catch color from the remains of the earlier sunset. The color is as it came out of the camera with noise reduction applied. I was amazed at my luck in catching an Iridium flare! “Iridium flares”http://en.wikipedia.org/wiki/Satellite_flare are brilliant glints or flares created on predictable intervals by the constellation Iridium communication satellites interacting with the sun. You can tell the hotter stars by their streak’s blue color, with cooler ones coming in more red. What amazed me is that star trails would come in this good so soon after sunset. I attribute the nearly new moon and the low light pollution of this area in New Mexico.
This was taken at ISO 400 at 28mm f/2.8 utilizing long-time exposure noise reduction in camera and further selective noise reduction via Neat Image in post.