From: Ferran Tomas Villalta <ferran.apple@gmail.com>

Date: December 31, 2011 11:04:16 AM MST

To: "Astro_IIDC@yahoogroups.com" <Astro_IIDC@yahoogroups.com>

Subject: Re: [Astro_IIDC] NGC 2903


Nice photo!


Happy new year to all from Barcelona Spain !


Enviado desde mi iPhone


El 31/12/2011, a las 19:00, "milton_aupperle" <milton@outcastsoft.com> escribió:



 

Hi Folks;

I was up until 4:30 am on Dec 27th and managed to image NGC 2903.

http://groups.yahoo.com/group/Astro_IIDC/files/DSO/NGC2903_20111228_MJA.jpg

Seeing was poor with measured FWHM in the +/- 5 to 6 arc seconds range (+/- 6 to 8 pixels in the image), but I did have good dark clear Mag 6 visual skies. I was shooting at 1625 mm focal length and did 16 minutes luma, 4 minute exposures red green and blue. Camera was cooled to -11°C

I had planned to image M81 and M82, but ran into all sorts of issues that night. First the cooler I built had a dead short in the wiring which required cutting and splicing wires (in the dark at -6°C) to get it working. Then my finder scope got bumped after Dec 23, so I could not do an initial star alignment and I finally got it synched to the main scope. Then I had all sort sof issues with finding M81 and had to re-synch on on Dubhe before I could find it. After that I was getting horrible trailing of the stars in the imaging camera, even though the guide camera was locked onto a nice Mag 9.3 guide star and showed no significant deviations in the log. After a few tests, I decide I would check the alignment as it looked like the main scope had awful field rotation. Well somehow my scope was knocked off alignment since I image M1 on Dec 23. I suspect the unusually warm weather that melted the snow caused the ground to thaw and the mount shifted on the grass / dirt, which was about 50 arc minutes west on RA and 5 minutes south on Dec. Once I got it all straightened out (at 1:45 am), M81 was in the trees.

The unfortunate part is that initially I had low turbulence skies in the 2 to 3 FWMH range, and M81 would have been spectacular at those levels. Oh well...

Hope you all have a super (and safe) New years Eve (and better luck imaging too)..

Milton Aupperle