The accompanying image shows the Rosette nebula in the infrared (720nm – 1,000nm) part of the spectrum. The image is composed of 7 subs at 1600 seconds per sub, just over 3-hours total exposure time – and – there’s virtually nothing there! You can just about make out some of the core region of the Rosette, and that’s about it. Amazing that there is so little near infrared emission from this object when I got plenty from another HII region – M42 in Orion.
I think this is the first timeI have found an image interesting for NOT having something in it. Any idea why such a big difference between this and M42 area? Whats the age diference between the two? Is it that the M42 is a very active star forming area, and Rosette is less so?
There is plenty of infrared emission at longer wavelengths from the Rosette nebula, it just seems very quiet indeed at the near infrared. I don’t know what mechanisms would make a nebula “bright” or “dark” at these very near infrared wavebands.