HCG Framing Tests

[DaveS]

And a test of my new ASI 533.

All images are 2 hours Luminance in 10 min subs at -10C using the Medium Gain setting in the ZWO driver, Gain 100, Offset 60. Stacked in AstroArt 8 with straight Flat and Dark frames. Bias was not used as it stuffed up the calibration. Crop, Gradient Reduction, DDP and Histogram Stretch in the cases on HCG 2 and 99 due to moonlight contamination.

North is up (Plate solve reported 179.5 degrees, so rotated where necessary). So, in order of RA (99 was done before 2 due to the meridian)

HCG 2

 

HCG 99

 

HCG 35

Could do with reframing, Stellarium was unclear

 

HCG 41

 

The complete frame as captured was 19' on a side, reduced slightly due to alignment cropping.

[DaveS]

For anyone else mad enough to go after the HCGs these should give some idea of their size on the sensor. ASI 533 on ODK 12 at 2040 mm focal length and theoretical 0.38"/px, which is totally bonkers.

[tomato]

Fair play to you Dave, I thought I had a small FOV with my Esprit 150/ASI 178 set up (0.47 arcsec per pixel unbinned) but some of these groups are tiny. Remarkable how similar HCG 41 is to the Box (HCG 61).

[DaveS]

Thanks, yes I can see the similarity. I was actually thinking of you and your monster dual rig, wondering if you might go after some of the groups.

Paul Hickson wasn't kidding when he said "Compact"!