chi Cyg with Alpy

Forums Spectroscopy Spectra of chi Cygni near minimum chi Cyg with Alpy

Andy Wilson

Hi Steve,

I think chi Cyg near minimum would make an excellent challenge for the Alpy, and it is only getting brighter. You would be able to see how the whole of the spectrum changes rather than just H-alpha.

A quick back of the envelope calculation. Your refractor has about a quarter of the light gather power of my RC. However, if I make the assumption that I can use resolution as an approximation to how dispersed the spectrum is across the chip (lots of assumptions..). My Lhires III has approximately 20 times the resolution of your Alpy, so you should get a spectrum that is about 20x brighter. So overall you might get 4-5x the intensity that I do. This is of course a very rough calculation, and it also assumes we get a similar throughput through the spectrograph slit, which is affected by a number of factors. I used my widest slit at 35 micrometers.