by Richard Crisp
Some time back I decided to attack this target with the mighty 18" f/12.6 Cassegrain with the goal of taking a tricolor or quad color emission line image.
I don't think I am going to get the Ha and Sulfur data to finish up this very difficult target this season so I am going to post the [OIII] data I lready have.
For those of you that have tried to image the Cat's Eye Nebula (NGC6543) you know that it has a bright core that is very tiny. What some may not realize is there's a spectacular outer halo surrounding it. I have only seen one amateur image that caught it and it was from Stan Moore taken in dark skies using fast broadband filters. I am using a narrowband [OIII] so the problem is compounded significantly with the bright backyard sky and the slow focal ratio and the narrowband filter.
This was shot from my backyard using 10 minute exposures. any longer and I would have saturated the core
I shot this at 5760mm focal length, at f/12.6 in the 18" cass.
The processing was very challenging primarily because I wanted to retain the integrity of the fine features of the core but at the same time wanted to show the enormous halo surrounding it. As a result the background in the outer halo is rather grainy.
I have a total of 22 exposures of 10 minutes stacked. The exposures were binned 2x2 yielding an image scale of 0.64 arc-sec/pixel.
I expanded the image to 2x the linear size once captured for the processing.
http://www.narrowbandimaging.com/ngc6543_cat_rdsc18_6303_ado3_22x10min_page.htm
Posted on sf-bay-tac Aug 13, 2005 16:47:06 PT
Converted by report.pm 1.2 Mar 07, 2006 20:01:10 PT