The Color in a Dark Sky

Under the dark sky of far western Oklahoma the 31st Okie-Tex star party started September 20th. As a speaker I was granted early arrival permission and setup Friday evening. Overhead the sky was spectacular that night. Even though it started to cloud over around 1:00am (Saturday morning) those few hours of dark clear sky, free from any man made light, is why I drive nearly 500 miles.

Unfortunately the next few nights were not very clear. As expected a storm system moved by us. It wasn’t until Tuesday night (9/23) we would have a good night. That night I wandered around taking pictures using a 5D Mark II on a iOptron Skytracker. This was the first time I’d used the SkyTracker in the field and of course I made a few user errors but the tracker worked good. I’ll post a review later.

One of my better shots of the milky way over the star party is below. Click it for a larger version and I will soon post an even larger version in my gallery. This picture is what the camera sees in the sky. A 3 minute tracked exposure, ISO 1600 using in camera noise reduction Lightly processed yes, to even out the serious vignetting of the Samyang 14mm lens at f2.8 and to sharpen and highlight the details. No gradient removal or masking was done at all. Note the wide variety of colors in the picture:

[ Milk way over the 2014 Okie-Tex star party ]
Looking north over the west observing field the photo is from ground level to nearly the zenith. Overhead the night sky was clear, the background dark. The dark spot above Cygnus was very distinct. Far to the north a few clouds pass by, just black spots. Around the horizon things got a bit murky. While the human eye sees shades of gray in the sky, especially near the horizon, its really full of color.

Across the top of the picture note the various red emission nebula spots, the detail and color of the Milky way. Going down the picture we see bands of green air glow and some hints of gravity waves in the atmosphere. On the ground red light abounds from the many astronomy enthusiasts awake. Busy observing or imaging.

This was a typical ‘good’ night for the star party, not great, just good. A great night at Okie-Tex requires a number of conditions coming together. Its not rare but difficult. For one you need the air mass above the Kenton area to be dry, really dry. For hundreds of miles in every direction. We were not in that situation when I took the above picture, note the NOAA water vapor image for that time frame below.

Far away from the glow of made made lighting the night sky is dazzling. Yet the natural night sky is not a uniform black or a shade of gray. Its a subtle, ever changing color. From moisture, air glow and the energy off the Earths magnetic field.