Thought I'd do something a little interesting in so far as imaging, so I created an RGB composite of the Rosette Nebula (NGC 2237-9) and its associated open cluster NGC2244. Although, it's not the normal RGB piccie you might think it is. In fact it's an RGB of the IR bands 25microns (blue), 60microns (green) and 100microns (red) taken by the IRAS satellite, back in the late 80's. In actual fact it's the resampled piccies (IRIS) of those same wavelengths except the image has been enhanced by more advanced imaging sampling done in the last 10 years or so.
What makes this piccie so interesting is that there is a wealth of information regarding the composition and structure of the cloud that is revealed in the IR. The cluster NGC 2244 shines brightly at all wavelengths, however, the gas and dust within the nebula shines at various wavelengths depending on the processes heating it up. Cold dust, for example, shows up quite markedly at 100microns (red), whilst hotter dust and gas show up at around the 25-60micron range. The inner cavity of the nebula is evident and the walls of the cavity show up as a discontinuous line running around the bubble. This bubble is generated by the powerful winds associated with the stars that formed the nebula and that lie within the cavity. The walls are basically shockwaves generated by the collision of the stellar winds with the surrounding gas of the nebula.
The FoV of the image is 6.85 x 6.25 degrees, east towards the left. The nebula is approx' 130ly across. There are quite a few other objects in the image, including 2 compact HII regions. If you want to know more about the image, feel free to ask
Rosette Nebula : RGB composite of IRAS IR data
