This is an image of Messier object 1, the Crab Nebula. Taken as a part of a test done in the back yard to check the way the PEC was working on the mount. I was also testing to see how well double stacking the Baader UV/IR filter with the Moon and Skyglow filter would work to give tighter stars.

I was pleased with the results of the double stack when using it on the SV4 refractor. On the Mak, it gave better results than expected. I was able to get better looking diffraction spikes for focus so it helped ensure good stars.

The stack is the result of 10 subs of 10 minutes each at 400 ISO using the full spectrum modified Pentax K10D camera on the 127mm Orion Maksutov Cassegrain operating at F13.1.

Only after taking these pictures and then looking at them a day or so later did I realize that there was something moving in the frames. It required a bit of work, but I believe that the object is identified in this list from the Minor Planet Checker:

Object (33078) 1997 WN35 RA 05 34 23.2 DEC +22 20 36 Magnitude 19.9 Motion in Arcsecs/Hr: RA 76+ DEC 0-

The finding of this object in the data meant that I had to get something out of the stack, which meant that I would work it over via trial and error.

Data was calibrated in Maxim using 77 darks, 15 flats, 256 bias. I had some flawed darks so I spent a long time chasing the errors. Stacking was done in DSS. Processing in PixInsight for DBE, background calibration, masked stretch, A Trous wavelets for de noise and sharpening, and a few more curve/histogram stretches before annotation. TIF files exported and then passed through LR3 for publish.

Here's the platesolve results:

Referentiation Matrix (Gnomonic projection = Matrix * Coords[x,y]):

+0.000009000243 +0.000208674202 -0.283327255590

-0.000208561976 +0.000008951188 +0.388714444083

+0.000000000000 +0.000000000000 +1.000000000000

Resolution ........ 0.752 arcsec/pix

Rotation .......... -92.479 deg

Focal ............. 1665.55 mm

Pixel size ........ 6.07 um

Field of view ..... 48' 4.3" x 31' 56.9"

Image center ...... RA: 05 34 32.519 Dec: +21 59 10.01

Image bounds:

top-left ....... RA: 05 33 18.987 Dec: +22 22 28.32

top-right ...... RA: 05 33 28.313 Dec: +21 34 27.73

bottom-left .... RA: 05 35 37.099 Dec: +22 23 50.72

bottom-right ... RA: 05 35 45.650 Dec: +21 35 49.67