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 brian.ingram







CURRENT MOON
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• 01/31/08
01/29/08
01/26/08
    
Thursday, January 31st, 2008
Placed 9.25" CPC out early enough to combat tube currents.  The seeing was poor tonight (seems to be the case these day).  Winds were whipping around all day at around 30mph but died out around 7:30 p.m. CST. 
 
Observed Mars and Saturn tonight and attempted to capture their images through a Celestron NexImage CCD camera.  I'm still trying to find the correct shutter speed and brightness/contrast filters to best capture images.  I used a shutter speed of 1/750 sec for Saturn with a low brightness setting and captured about 900 frames through the camera.  Using Registax, I was able to get a Saturn shaped object with no features (save for the ring) but a brilliant yellow color.  I'll try again with different settings and on a night with better seeing.
 
Mars was little better -- a nice burnt orange color with a brownish smudge (looks "Y"-shaped) at the 1 o'clock portion of the image.  Using my imagination, I think I can see the presence of the ice cap.  I'm hoping that this image is unacceptable (given the aperture of this telescope) because of poor seeing, or at the worst -- the telescope is one BIQ out of collimation.  I'm hoping it's not because of optics quality [like being a parent of a newborn baby, I'm hoping there are no defects that will be discovered as time passes  :-)  ].
 
Just for fun, I captured an image of Sirius and processed through Registax.  Upon first inspection, I captured a pretty blue spot that looks almost like a disk.  As I zoom in and let the image become pixellated, I begin to notice a prism effect on the image:  At the 5 o'clock position, the star is slightly red.  The prism effect travels to the upper left and ends at the 11 o'clock position.  Starting at the 5 o'clock postion and moving to the 11 o'clock position, I see yellow, then green and the exact center is the white-blue I recognize as Sirius.  And then as I continue on up to the 11 o'clock position, we get into the blues and violets.  Is this coma?  Aberration?  Mirror misalignment?  Or is this just how the computer mixes the colors to give the image at normal view (this was zoomed to 1600x).  These images were taken at prime focus, so eyepieces were not involved.  Anyone reading this who want to see it for themselves is free to e-mail me -- I'm also open to analysis of this issue.  (Thanks in advance).
 
I spent about three hours out in 30F weather with 10 mph winds, I got tired of freezing and ended the observations after capturing enough images.
 
 





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