Fig. 1
From: Auroral responses to the visit of comet 73P/Schwassmann–Wachmann 3 in 2006
a: Optical spectrum of the comet 73P-C/ Schwassmann–Wachmann 3 after sky removal. b: Ratio of the comet 73P-C/Schwassmann–Wachmann 3’s spectrum and of the HD 197076’s spectrum. The data for a and b are both from http://www.astrosurf.com/buil/sw3/result.htm. c: Identification of the fragments of the comet 73P-C/Schwassmann–Wachmann 3 taken by the Spitzer Space Telescope in 2006 May. The meteoroid stream is clearly visible and seems to “connect” the fragments