Forums Comets Spectrum of Comet 46P/Wirtanen Congratulations

John Coffin

Nice spectra. I tried to collect a spectrum of 38P/Stephan-Oterma last week. The  spectrum of the nucleus was basically a straight line and the coma indistinguishable from the sky background spectrum from a part of the sky a few degrees away, (total exposure 4200 secs). On reflection I think I was a bit optimistic, the nucleus is mag 14.5 and the total mag is 10. I wondered if a a short focal length telescope is better for spectra of faint comets. What magnitude does a comet need to reach before it’s reasonable to expect to capture a spectrum with amateur equipment?