Attached find two photos of the observatory setup. You can see that we have a small plywood box that has plexiglass dome on it for an observatory. The mountains in the background are the Brooks Range. Inside the observatory, we have two high speed cameras, and a high speed photometer.
The funny looking "pink" things on the front of the cameras and photometer are really Kodak #32 magenta filters. They let through both blue and red, but block out green light. The four prominent wavelengths in the aurora are 427.8, 557.7, 630.0, and 750-850 nm. The first and the last emissions are prompt emissions from Nitrogen, and have very short lifetimes. Since we are looking for fast changes in inensity of the auroral light, we want the cameras to be looking at the prompt emissions. The middle two emissions are from Oxygen, and have longer lifetimes. Looking at the light from these will smear out the response we are looking for, so we filter out the bright 557.7 nm forbidden Oxygen line with the magenta filter.
Does anyone know why the lifetime of the Oxygen is longer? If you do not, you can look up the answer in a quantum mechanics book. I have set the permission on the blog so anyone can make comments, so if you have any questions don't hesitate to ask.
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