A dark and starry night

And stormy? Distant lightning was evident on the horizon, despite better than average transparency overhead and the beautifully clear sky from horizon to horizon. Yet, distant flashes punctuated the otherwise perfect night. No matter, the lightening must have been quite some distance away. My goal was another shot at the Pinwheel Galaxy (below).

We were joined at Norton Cemetery by visiting astronomer Robert this time around, with his beautiful refractor (6″, I think) and GEM mount, complete with 2” eyepieces and a comfortable viewing chair. For this neophyte astronomer, views through his telescope were amazing. We also had several observers join in and a few snapping Milky Way pictures using various cameras from point-and-shoot to more advanced DSLR cameras.

This was another night of imaging the Pinwheel Galaxy for me. I’m fixated on this M101 object lately, simply because my most recent experiments with processing started out with this, and it makes sense to keep honing in on the same object for comparison. And, it’s pretty!

My plan was to take even more exposures for stacking experiments, but this time at f6.3 focal ratio by way of my f6.3 focal reducer. This will bring in more light and a wider field (less magnification). But M101 is perfectly framed under these conditions, so all the better to try f6.3. Images in the recent M101 blog post were 90 seconds and at f10, but there were many more to stack.

Of course, Murphy had to show his ghostly presents – it is a cemetery after all…and I noticed that the exposures aborted after only the 26th shot. The LED panel voltmeter in my battery box showed the voltage flickering at just under 9 volts rather than the typical 12-plus. This after about four hours of operation, which should have been fine for a fully-charged battery. (The M101 exposures totaled at 52 minutes.) I’ll have to look into that, but meanwhile the 26, 2-minute exposures at 1600 ISO and f6.3 did result in more signal, which was quite evident while processing the raw images. So, we’ll call that a steady improvement even if difficult to see on this web page compared to the previous version. If only I had more shots to average out the low-level noise. Darned Murphy!

The Pinwheel Galaxy, M101.
26 exposures at 1600 ISO, f6.3 from my Canon T5i DSLR camera. Telescope is a CPC-800XLT, tracking using PHD2 via Astroberry and a Raspberry Pi. Processing is done with SiriL.

These deep-sky objects really are in the noise, so bringing them out to this point is an achievement. I had several folks peer through the eyepiece before attaching the camera. One could barely make out the central core and perhaps a hint of the spiral arm structure.

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