Object name: ARP155
Designation(s): ARP155, NGC3656,
I started a run on ARP 155, also known as NGC 3656 and went to bed. When I got up I found the temperature had dropped nearly 20C during the exposure. This was a major test of my temperature compensating focuser which constantly readjusts the focus based on the temperature every few minutes. I figured thermal lag in the scope would have it ahead of the curve but it was right on. The only problem is my image scale changes and the final image was a good 40 pixels bigger than when it started. So simply stacking them didn't work. I had to resize every frame to compensate. What a pain. There is software to do this but it is expensive (I since got it anyway). A bit more than I wanted to spend at the time this was taken. Also as the image size changes so does the vignetting meaning the flats for the start were right but those for the end didn't begin to compensate for the vignetting correctly. I had to use pseudo flats to compensate. That meant I couldn't dig down into the noise level like I would have liked. But it is my first image under perfectly clear skies in 7 months so I can't complain too much.
Related Designation(s):2MASS J11233856+5350319, 2MASX J11233859+5350313, ARP 155, ARP 155 NED01, ARP155, CGCG 1120.8+5407, CGCG 268-029, IRAS 11208+5406, IRAS F11208+5407, KPG 282, KPG 282A, MAPS-NGP O_130_0508687, MCG +09-19-063, NGC 3656, NGC3656, NSA 159747, NVSS J112338+535032, PGC 034989, SDSS J112338.73+535031.8, SDSS J112338.81+535031.7, SDSS J112338.82+535031.8, SPRC 201, SSTSL2 J112338.57+535031.1, UGC 06403, UZC J112338.5+535032, VV 022, VV 022a, [TTL2012] 204690,