I was going to delay posting this image because of the plethora of Rosette images about at present. It seems we have all got the bug, myself included. I managed to get a couple of nights imaging in despite Win 7 not recognising the camera on one night, which resulted in losing about 5 subs.
As to the nebula itself, this is located in the constellation of Monoceros at a distance of between 4900-5200 light years. It seems no definite distance as been ascertained as yet. The nebula is about 130 light years across and contains quite a few high radiation emitting stars which drives the emission nebulosity. In traditional RGB light the nebula presents as a rosette or rose. With the Addition of narrow band data the nebula does as coined by Mike present a tunnel or sorts and a lovely display of bubbles of gas.
The object had long been on my imaging list but I was not able to capture it all prior to obtaining a reducer for my TSA. And; it is quite north in declination and just clears my roll off roof on the observatory. The processing is I think to my liking on this occassion after several reprocesses, but it still contains some darker rings (blue stars outer halos present quite dark when super imposed on deep red) in the darker parts of the nebula. I did try Peter W to keep this to a minimum (you are always picking me up on that
), but I think I will need to learn some more processing ideas on reducing this problem. Isolating the stars through layers is going to be a must for this type of emission nebula.
Of note is that on my Ha data I had really large halos (aka reflections) on the brighter stars. This was over 2 nights and it appears just like in Chris Venters image. Although I note he says his are in his RGB set and not Ha. Not seen these halos before and might need to investigate the cause. Ideas would be appreciated.
Click here for the image.