PEC training using a CCD camera

TODO

The Bubble Nebula Revisited

NGC 7635 on June 25, 2004. My first SII Ha OIII image attempt.

2004-06-25:

The Bubble Nebula

NGC7635 on June 4, 2004. A combination of eight 20 minutes exposures through a 656.3/4.5 nm H-alpha filter for a total exposure time of more than 2.5 hours. The ST-7XE camera was cooled to -20C.

The Cocoon Nebula

IC5146 on May 29, 2004. A star-forming region of glowing hydrogen at an approximate distance of 3000 light years, surrounded by a sparse star cluster. The hydrogen is lit by the type B0 star of magnitude 9.6 in the center of the nebula.

This is an 80 minute exposure, consisting of four 20 minutes individual exposures, through a 656.3/4.5 nm H-alpha filter. The ST-7XE camera was cooled to -20C.

NGC 6888

NGC 6888 on May 29,2004. This is a mosaic of two 100 minute exposures, each consisting of five 20 minutes individual exposures (2x5x1200s) through a 656.3/4.5 nm H-alpha filter. The ST-7XE camera was cooled to -20°C.

Dumb Focuser Thumbscrews

Last night I realized that much of the flexure in the optical train I have been noticing many times before is really caused by the focuser. It is never snug to the back of the telescope. So today I took a closer look and noticed something I should have noticed a year ago. The damage to the optical back is not caused by over tightening, but by the focuser thumbscrews that were included in the JMI case itself! Comparing them to the original ones that came with the telescope, it is obvious that these replacements have a flat head instead of a round one, and they do not properly fit in the optical back.

So I filed them. And indeed now the focuser connects well. Moving forward, this should reduce the elongated stars I have been seeing in so many of my images.

Planetary Nebula M57 Revisited

My first image using my new AO-7. Not perfect yet, but sure an improvement on my previous image.

2003-04-08: 4 minute exposure (2x120s). Camera cooled to -10-20°C.