Sunday, July 30, 2017

Back from the 2017 Nebraska Star Party

Ah, to be back in the land of 10,000 lakes and high dew points!

NSP 2017 is over, and it was a memorable one. Sunday (7/23) was clear and about as good a night as I've ever enjoyed at NSP--or anywhere, for that matter. The day had been in the low 90s, but the temperature dropped quickly as the sun set. There was a strong and gusty breeze that kept the mosquitoes away. (I realize big scope owners didn't like the wind, but I was imaging with a 200mm lens wildly overmounted on a CGEM.) The transparency was exceptional overhead; the Milky Way was nothing short of spectacular.  I don't think you could read by its light as one person predicted, but it was definitely casting a subtle, diffuse shadow.

I was able to collect some light frames of my current target, the Rho Ophiuchi Cloud Complex, then switch over to the Sadr area for the Butterfly:

The Rho frames have yet to be processed. The next night I decided to spend the entire night imaging the Veil:

What I like about this 200mm lens is how flat it is at f5.6, and free of vignetting.  There are two new things about these images:
  1. Instead of stopping down the lens with its internal iris I used a step down ring. This gets rid of the diffraction spikes caused by  the blades of the iris.
  2. I used PHD and BackyardEOS to dither the images.  It seemed to work very well!
The last night was cut short by clouds, so I only got five frames of the Rho area at 135mm:

As you can see, this lens has substantial vignetting.

By the way, 2017 NSP was on the hot side.  The Monday and Tuesday highs were 106 and 107 degrees, respectively. But it was the usual "dry heat" and both days had those great strong breezes.  I spent the afternoons sitting and reading semi-comfortably in the shade of the supper area canopy. Thank goodness NSP didn't happen the previous week when it had been both hot and humid.

Now it's on to eclipse planning and back to meteor counting!

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