[Terry B]

Dear All
I aimed my LISA spectrograph at this now very popular comet to see what it looked like.
Comets are illuminate mostly by reflected sunlight but the composition of the comet changes the spectra so you can detemine some common elements in the comet.
Most of the comet spectra comes from carbon compounds that have been vapourised from the surface of the comet. Many of these are known as Swan bands. There is also CN and CH compounds.

Another interesting effect is the width of the actual spectra. My spectra was taken by aligning the coma of the comet on the slit of the spectrograph. For a star this would create a spectra a few pixels high but because the comet has a diffuse coma then the spectra is broad with the spectra from the diffuse coma visible above and below the comet body spectra as a weakening band vertically. See the attached image.
Cheers

Terry