On Saturday I posted a picture of my first try at photographing the sky with a tracking mount that allows long exposures. It came out great! “I wonder if I had beginner’s luck with my celestial pole centering?” I mused.
Ahem. As I mentioned on Saturday, the tracker has to be aimed precisely at the north celestial pole, which is offset slightly from Polaris. I thought I knew the correct offset, but I didn’t realize that it changes with the hour. Nor did I realize that everything is upside-down and backward in the polarscope. In other words, I was basically throwing darts when I lined up the scope and I just got lucky. So last night I bravely left my front yard and went out to an area that’s mildly dark to try again under more realistic conditions. This time I used an app to tell me the proper offset, and everything seemed fine when I sighted Polaris. But here’s what I got:
I tried again and got the same results. You don’t really need a pixel crop to see how bad this is, but here’s one anyway:
What happened? Did I miss Polaris completely? Maybe I mistakenly had the scope centered on that star just above Polaris (Delta in the Little Dipper?). That’s quite possible. More practice needed!