Prior to the approaching storm (yes, we DO get rain here), Jay LeBlanc of Sonoita and myself decided to do a little deep sky observing. We were using Jay's 17.5" modified Dobsonian from his driveway, about a mile from my place. The night started somewhat brighter than normal due to the amount of particulate matter in the sky and the increased moisture in the air. However, as the night went on, the brightness decreased, transparency improved, and we had a pretty good night.
The first object was Zwicky galaxy cluster number 6504 (the catalog numbers come from The_Sky V5). This was in the field with a somewhat easy NGC 5477. The cluster was evidenced by three very subtle and dim glows floating in the field with the NGC galaxy. These objects were not distinct and were definitely not easy but Jay and I both saw three soft glows. We were using a 9mm Nagler for about 221X.
Next was the dim thing MCG9-23-42 at magnitude 15.5. To me it looked like a somewhat elongated brightening in the sky. Moving to even tougher targets, the Zwicky cluster 6560 was tough: very dim and very subtle, bordering on invisible. Zwicky cluster 6587 was the easiest of the night: reminded me of Stephans Quintet through about a 10 inch telescope: something there but that's about all. KUG1336+282 at magnitude 16 was seen with direct vision. This galaxy seemed brighter than its listed magnitude and was slightly elongated with a stellar nucleus.
Changing gears, the loose globular NGC 5466 was a welcome change from the faint stuff of earlier in the evening. Somewhat large, it reminded me of say M11 or perhaps M6 or M7 through binoculars. It was a welcome change from the dim world of Mr. Zwicky's galaxies.