AS110 session May 8, 2013
Posted 09 May 2013 - 04:12 AM
despite of weather forecast, the last night was very nice. I decided to go to my darker sky place, into an observatory were I keep 110mm refractor Zeiss AS110. I started already at twilight with a few doubles I observed recently in my smaller telescopes. On the way to 49 Leo, I accidentally run o nice bright orange star which I quickly identified using Uranometria 2000.0 as DE Leo (or 44 Leo). The star was followed by nice unequal pair (I estimated the difference in magnitude to be about 1-2 mag). At 83x (ATC Kellner 20mm), the bluish color of main component was in nice contrast with orange color of DE Leo. I could not find the double in Cambridge atlas of doubles later at home. But with Carte du Ceil, I finally identified it as STF1431.
Double 49 Leo was lovely clear pair at 236x (TMB Mono7mm), I could even glimpse the faint secondary already at 83x.
Next double was another unequal pair 25CVn. At 236x, the telescope had no problem to show clearly the faint secondary just beyond the first diffractive ring. I estimated the distance to be about 2".
I could not split the two tight components of triple 35 Com even by pushing the magnification up to 353x (TMB Mono 7mm + ATC 1.5x barlow).
Although it was not still completely dark, I checked nearby galaxy M64. In particular, I was trying to spy the black eye feature. All I could see was just stellar nucleus surrounded by mottled roughly circular brighter area. I had a feeling, from time to time, that the stellar nucleus splits into tiny double.
Then I jumped south, because it is hard to access that part of the sky from city. I checked globular M68 which I observed so far only once. At 41x (ATC 40mm Kellner), it was clearly visible rounded disc with no central condenzation. The best view was at 83x, I could already see from time to time several stars (about 10) peppered across the cluster. Larger magnification 132x (Baader Genuie Ortho 12.5) showed one star in the outer halo quite clearly, others were still hard to spot but they were there. It is definitely a nice cluster.
Next stop was galaxy M83 which I observed for the first time. Pictures show very dramatic system. However, all I was able to see that low on horizont was just a faint rounded misty spot with a star (nucleus?).
After that I swiched again to Coma cluster Abell 1656 which I was investigating recently from my backyard in 63mm and 130mm refractors. In particular, I wanted to find out how much I could see from the darker place. There was definitely more to be seen, it was time consuming, but I clearly noticed besides the two obious galaxies NGC4874 and NGC4889 (this one is easiest, it was already visible at 41x as elongated elipse) these galaxies: NGC4874, NGC4889, NGC4865, NGC4860, NGC4864, NGC4869, NGC4898, NGC4907, NGC4908, NGC4911, NGC4921. Most of the time I used magnification of 103x, CZJ O-16, but some times I had to increase it a little bit. Interestingly, most of the small galaxies (like NGC4864, NGC4869, NGC4898, NGC4860) were visible as hazy stars. Almost stellar but definitely not stellar. I could not see most of these faint companions in 130mm refractor last time from my backyard. I also observed NGC4921, which is even brighter than NGC4889, but it has a low surface brightness and I could not glimpse it in 130mm. Under dark skies, it was difficult to notice it, but it was clearly there as relatively large very faint circular glow.
There was probably much more to be seen but after about one hour of intensive observation I was exhausted. I switched to Saturn which was just culminating. I did not see Saturn through AS110 yet and I was not prepared to what I saw. Seeing was not perfect, I found the best view at 132x. But what sight it was! Last year I observed and sketched this planet quite a lot in my 100m ED refractor. It is hard to judge by memory, but the view in AS110 was completely different level. I do not remember so nice and vivid colors and very subtle changes in coloration of northern belts. Cassini division was also very nice and traceable for a long distance. Also ring C was providing nice tiny grayish rim in place where the rings were passing above planet. This was definitely highlight of the evening. Unfortunately, I was already too tired to try to sketch what I saw.
In the next, I checked again tiny planetary NGC6210. Even at 353x and 413x (Kassai HC ortho 6 + ATC 1.5x barlow) I could not glimpse the central star. All I could see was slightly elongated mottled disc with slightly darker center. There were some small brightenings visible on the disc but I did not bother with sketch again.
Then I jumped to M13. At 236x it was another highlight of the evening. This cluster is wonderfull, I do not know if it is a darker place or just 1cm larger diameter, but the view is so much better to the view in ED100 (which is already very nice). The cluster is peppered with hundreds of stars across its entire surface. They are easy to see. On top of that there are numerous chains of fainter stars running out of the central reagion. I counted at least 7 easy ones. The cluster looked like a head of Medusa.
At the end, I just recheck difficult cluster NGC5053. It was clearly there at 41x as a faint rounded hazy disc. There was a star popping in and out with averted vision. It almost disappeared at 83x, but there were more faint stars visible in the area.
And finally, I checked two doubles. Zeta Herculi was too difficult, but lambda Oph was lovely nice slightly yellowish pair of almost touching bright discs.
Posted 10 May 2013 - 02:44 AM
I've only seen two members (but that was with the Zeiss Telemator, as you may remember). I'll need to get the big scope on it, but now the summer twilight has already begun and I fear it may have to wait another year.
Posted 10 May 2013 - 11:15 AM
Thanks for sharing!
Posted 12 May 2013 - 02:56 PM
Posted 15 May 2013 - 11:29 AM
I hope to try soon and post it here - weather allowing!