Expanded spectrum on M16

We got a set of UBVRI filters to measure star temperatures, but you can also have some fun. I haven't seen this version of M16 yet. The R channel is 12min through an IR filter, G is combined BVR, 12 min each (which I would like to re-try sometime with just an IR-blocking luminance filer) and the B channel is 30 minutes through the UV filter. Everything was in 2 minute chunks, as I am still fiddling with autoguiding issues. Things were scaled to the reported QE of the ST-10XE camera. Luminance was just everything added together here, but I realize that there are better ways to do that. Not much processing.

The interesting things are the very red stars like the one to right of upper center that doesn't show up at all in most shots. Also those really bright stars do put out the UV. Since I just took this last night I haven't looked up the details of spectral classfication on the stars in this one, but M16 is certainly one of the younger ones. If anyone has suggestions or comments, they would be welcome. I already know I have a lot to learn about the effects of IR on my CCD. Some of the "odd" effects on those bright stars are likely from that.

Charlie

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Charles, that's a very cool & interesting shot!
First time I see anything like this...


Thanks for sharing! 8)

Cool image. The UV-bright stars seems to make donuts --
perhaps are de-focused. What sort of scope is this --
SCT or APO?

Here is the dumbell with basically the same process. Took this the same night. About half the data though. Unfortunately much of the UV got hosed, so I scaled it extra and added the blue and UV together for the blue channel. The nebulosity has almost NO detectable IR. Interesting. There is, however, quite a bit in UV. And that white dwarf stands out a bit more than it usually would. If I can get some more UV data, it should be even more abrupt.

Charlie

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