10 replies to this topic

[PhilH]

In 1982, astronomer Paul Hickson, professor of astronomy at the University of British Columbia , published a study of 100 compact galaxy groups scattered throughout the sky. In his paper "Systematic Properties of Compact Groups of Galaxies", Hickson defined a compact galaxy group as a small, relatively isolated collection of four or five individual systems that are set in close proximity to one another, and that differ in brightness by no more than 3 magnitudes. Further, so as to avoid including the central regions of dense galaxy clusters, Hickson stipulated an "isolation factor" requiring that there not be a non-member galaxy of similar magnitude within three radii of the group's center. Surveying the Palomar Observatory Sky Survey, Hickson created an inventory of 100 such groupings. The entries in the Hickson Compact Group, or HCG, catalog are ordered numerically according to increasing right ascension.

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[Astrojensen]

Under a dark sky, I've seen NGC 3190 and 3193 in my 63mm refractor, using 53x and 84x. The other two are not visible. NGC 3185 was visible with effort in my old 4.5" f/8 Newtonian at 50x. NGC 3187 took a 12" Dobsonian to see. 

 

I plan to take a photo of Hickson 44 with my Zeiss Meniscas 150 and smartphone, when I get the chance. I'll also take a look visually with my 6" Dobsonian.

 

 

Clear skies!

Thomas, Denmark 

[Sasa]

I have seen only three galaxies so far. The best view was through 110mm refractor from my (former) darker sky observatory. The brightest member, NGC3190 was even showing some detail: oval shape, right rounded core from which there were two brighter lines going along the major axis. NGC3193 was a round glow with strong central condensation and stellar nucleus. There were no detail in case of NGC3185, just faint rounded glow without any significant central condensation. After a while, it became quite well visible with averted vision. Here is the sketch from that night:

 

[Astrojensen]

I managed to take a mediocre image of Hickson 44 on the evening of March 6th, in bright moonlight, using my smartphone and Zeiss Meniscas 150/2250mm Maksutov.

 

Visually, I could see NGC 3190 quite easily through the Meniscas at 70x (32mm Masuyama 85°), with NGC 3193 being dimly visible as a round glow. The other two weren't visible on this evening. 

 

The image isn't much to look at, but here it is. I had to crop it quite severely, to get rid of some ugly gradients. Flats failed to correct for the vignetting, for some reason.

 

Hickson 44 galaxy cluster, March 6th, 2025. Zeiss Meniscas 150/2250, 40mm GSO projection eyepiece, 56x. 56 x 30 seconds, 6400ISO. OnePlus Nord CE3 Lite smartphone, Deep Sky Camera app. Stacked in DSS, processed in Windows Pictures. Crop of a larger field.

 

 

Clear skies!

Thomas, Denmark

[optinuke]

I had viewed Hickson 44 from pristine Arizona skies with a 24" Dob and 16" SCT. All four galaxies were immediately evident with magnifications of 277x (24") and 200x (16"). I was curious as to how they would look from the Midwest skies of western Kentucky where I now reside.  In the 16" SCT, NGC 3190 and NGC 3193 stood out, with NGC 3185 more subtle but visible at 100x and 145x.  Increasing magnification to 270x gave the best view of NGC 3187.  My visual impression was similar to the detail in Astrojensen's image in the preceding post.

[optinuke]

I've been experimenting with focal reducers on my f/11 C14. I found that with lenses installed at both positions in a Giant Easy Guider (plus a little additional spacing), I could get the focal ratio down to f/3.6, primarily to give a larger field of view for my OSC camera.  Hickson 44 seemed like an excellent subject. Here is a cropped image that is a little rough - still some artifacts - but the group shows up well. PGC 2806871 is also visible.  PGC 86788 is a "maybe" smudge.  North is up. 90 x 20sec unguided subs for a total of 30 minutes. I also noted all four NGC galaxies showed up on single 60 second exposures.

 

[Dave Mitsky]

I've observed Hickson 44 many times with a variety of telescopes.  It's my favorite Hickson group.

Here's a 43-minute-long-exposure of Hickson 44 that I captured with my Seestar S50 tonight from my red zone home.  It's been Seestar S50 AI denoised and enhanced a bit using Photoshop.  I got a high SQM-L reading of 18.91 mpsas.

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[Dave Mitsky]

This is a cropped version of the above Seestar S50 image.

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[Dave Mitsky]

I acquired this image of three of the galaxies in Hickson 44 in 2013 using what was then known as the Bradford Robotic Telescope, a Celestron C14 SCT situated on Tenerife in the Canary Islands.

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[Dave Mitsky]

I imaged Hickson 44 again this morning from the orange zone Naylor Observatory.  

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[Dave Mitsky]

Here's an AI denoised version.

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