12/17/2006 Glittering Diamonds, Well Actually Cubic Zirconia..

Last night was another clear one so for the 5th night in a row I set up for some imaging. But I decided that in addition to the wide-field refractor stuff, I needed to get some science projects going on the RCX.
This image is actually from the refractor, though. My target was R Geminorum and although I did get some better data on it with the RCX, it will take a bit longer to process that. Meanwhile I decided to take a few images and spectra with the refractor for comparison purposes.
R GEM is a Mira-type variable, which means it has a long period. The "R" prefix tells us that it was the first variable discoverd in Gemini (note to self - look up the historical significance of the letter R). It's of current interest because it is very close to reaching its brightest magnitude - predictions place the maxima at December 17th. So I decided to tackle some photometric imaging as well as some spectroscopy on this interesting star.
It's a Type S Red Giant (Type S is a later designation that is not part of the classical H-R Diagram), and since it's late in life it has a relatively high abundance of metals. Note that astronomers generally refer to anything other than Hydrogen and Helium as a "metal". I'm hoping that my spectrum taken with the RCX will reveal some zirconium oxide signatures - zirconium as in cubic zirconium.
So this image was taken with the DG1 Spectrum Filter and the 4" refractor. If I has used a color camera, the spectrum would actually have a rainbow color, but my camera is black and white. Still, you can see an obvious brightening in the farther (redder) end of the spectrum. I'll extract the spectrum and run it through vspec to see how it looks graphically later.
In addition to R Gem, I got a lot of data last night, including spectra of Saturn and Eta Hydrae, and images of a few deep-sky objects. There is an awful lot of data for me to process, in fact my hard drive was down to only 1Gb free space this morning!
Tonight was supposed to be a star party at Steve's for the Astrophoto SIG, but a storm is moving in so I didn't bother packing up.