by Richard Crisp
I've been on this project for a couple of weeks. I had a goal of revealing the outer ring in a color image taken using emission line filters.
Although I have the outer ring in my data, to bring it out is messing up the detail of the core of the dumbbell and it is terribly grainy. So I have decided to surpress the outer ring until I can shoot it from a truly dark sky such as Plettstone. I guess even with the emission line filters it is just a bit too bright here to get a decent signal to noise ratio in the very faint nebulosity.
Ignore the star colors, they are hard to get right using emission line filters. I will probably improve them in the coming few sessions by adding some RGB data.
This is 5.75 hours of Ha, 3.25 hours of [OIII] and one hour of blue for a total of 10 hours.
http://www.rdcrisp.darkhorizons.org/m27_dumbbell_nebula_hao3b_page.htm
if you must see the outer ring, I have brought it forward in an intermediate image that did not have quite so much exopsure time in it.
http://www.rdcrisp.darkhorizons.org/m27_dumbbell_nebula_ha_page.htm
Who knows, I may decide to try again to bring out the ring in the 10 hour shot....