Blog Sunday 27th January 2013

 

Tonight is Full Moon, there are a few of us in our close observing group that feel such a night frequently bring clear skies, where as conversely New Moon appears to bring cloud! Fact or does it just appear that way to us who are desperate to observe?

Anyhow the past few months have been so poor in terms of observational opportunity that full moon or not I was taking this one! I had decided that I would go for a couple of open clusters, not my usual fare, but they stand up OK in a bright moon lit sky. I had collected my treasured Watec 120N+ deep sky video cam from Es Reid who had been checking it over as I had been suffering with connection issues.

For no particular reason I loaded the camera into the 80mm F6 Stellarvue refractor that I use as a finder, this is a short achromat but a good one. I have a Vixen flip mirror on the back of this small scope which should allow me to use it visually and have the Lodestar guide camera in operation to. However I have even with learned assistance not been able to get the Lodestar to work!

Orion was well placed so I used Rigel to get the camera focussed, goto worked well, although the camera only just came to focus when racked right in. I stayed in Orion and looked through some of Sue French’s notes for suitable open clusters, knowing Sue to be a fan of the like!

I stopped off at an Asterism –cum- cluster Doldize 17, I don’t think I have ever sketched or more correctly drawn in the dots for any groups from this catalogue before. It turned out to be a sparse collection of reasonably bright stars that the brain could happily make geometric patterns out of. I was here so I carefully put down my dots, and worked out the orientation of the view.

 

 

Doldize 17

 

It was good to see that with the wide field of view and effectively ‘low magnification/focal length’ I could push the integration time up past 20 seconds without ‘trailing or smudged stars’ allowing to go a little deeper with the small scope, you can’t get away with this when using the 20”. Mentally I calculated the monitor view to roughly equate to the visual through an 8” scope. Next I put the scope onto NGC2141 which in NSOG looked rather globular like in a sketch made through a 12.5” under dark US skies, the view that I saw was not unattractive but the bulk of the members were faint, giving a milky backdrop to a few brighter members and identifying exactly were the main body of the cluster started and finished was rather vague. It was at this point that I wished that I was working with the 6” refractor and no the 80mm, but hey ho, I had started so I would finish with such. I decided that I should move onto a cluster with brighter members. So next I alighted upon NGC 2194 which although not overwhelming on the monitor screen, was a little courser, gritty, definite and likely to make a slightly easier and more respectable target for me to draw.

I spent the next 40 minutes or more getting the stars into correct positions on the observing form, I don’t get every member down, but I continue until I’m satisfied that I have captured the clusters ‘personality’. Many would consider this to be tedious I find it relaxing and rewarding.

Well here is my rendition.

NGC 2194

 After the drawing that was to be it for the night, the sky was now so bright with the moon well up. I fitted the binoviewers onto the 6” refractor and took a short look at Jupiter with 4 moons strung out and its belts rendered sharp and detailed by the large triplet, with seeing looking quite steady. No GRS on view , that would have prompted a sketch, but in the absence I put the scopes into park, closed up the observatory and retired to bed.

 

Dale