This very low resolution (R~130) spectrum was taken ~20 days after an outburst which saw the brightness increase by ~ 6 magnitudes to an integrated brightness of ~11R
By the time of this observation the original relatively condensed coma had expanded dramatically and the corresponding reduction in surface brightness reduced the available light passing through the spectrograph slit. I therefore used my very low resolution faint object ALPY200 spectrograph. 
The spectrum is that of reflected sunlight from dust with no evidence of emission features, compared with this observation of  C/2020 R4 for example, though this colour image in the comet section archive taken five days earlier does show a hint of blue green Swan band emission.
Observer
Robin Leadbeater
Observed
2021 Oct 15 - 02:42
Uploaded
2021 Oct 17 - 14:59
Objects
29P Schwassmann-Wachmann
Spectrum
Equipment
    ALPY 200 spectrograph
    ATK 314 camera
    Celestron C11 SCT 280mm aperture f5.5
Exposure
3000s (5x600s)
Location
Wigton Cumbria
Target name
Comet 29P/Schwassmann-Wachmann
Title
Comet 29P – a low resolution spectrum
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Page last updated: Fri 26 Sep 21:57:06 BST 2025