A few days ago we had a spate of clear nights ( sort of ), this gave me the chance to image the Rosette nebula in Monoceros. Now I have imaged this object before, but that was with a small telescope, a 72mm William Optics Megrez refractor – this time I wanted to image this nebula and open cluster NGC 2244 ( the stars of which is formed from this molecular cloud ) with my 8 inch RC telescope for more detail. This rig has a higher magnification and therefore a smaller field of view, this means I cannot get the whole nebula onto the camera sensor, so I have to image several sections ( slightly overlapped ) and put them together as a Mosaic.
I will need 8 images to make this mosaic to cover the whole gas cloud, each image will be made from 30 light frames, each of 3 minutes exposure. I also want to image using the Ha, OIII and SII filters. so lets work this out, 8 mosaic panes x 30 light frames x 3 filters = 720 light frames at 3 minutes exposure = 36 hours total imaging time, obviously more than can be done in a single imaging run, infact if I get 6 hours of clear imaging a night, that’s 6 nights work. 6 clear nights would be a luxury the way things are with the weather at the moment, thank heavens the images are digital and can be saved.
As it stands – the spate of clear nights only gave me 2 usable nights, the remaining nights were misty and foggy, sadly sunny days on wet ground lead to misty foggy evenings.
so I have out of the 2 usable nights, 3 mosaic panes of the Rosette nebula in Ha – this definitely going to be a work in progress.