two days of detection of the SN and showed only a few broad absorption features. However, the spectrum from Las Campanas Observatory on 2001 Dec. 13 [@Phillips01] revealed similarities to the Type IIb SNe 1987K [@Filippenko88] and 1993J [@Filippenko93].

Over the following month, spectra from the European Southern Observatory [@Clocchiatti01; @Clocchiatti02] showed [SN 2001ig]{} to evolve in a manner similar to both SNe IIb 1987K and 1993J, as the hydrogen lines became weaker and showed the complex shape characteristic of the transitional stage [@Filippenko94]. By Oct. 2002, the predicted transition to a Type Ib SN in the nebular phase was complete [@Filippenko02]. At the time it was also noted that the \] $\lambda$4571 feature was the strongest (relative to \[\] $\lambda\lambda$6300, 6364) ever seen in a SN. Our data complement the optical spectropolarimetry and total-flux spectra that were presented and analyzed by @Maund07.

In addition to optical data, X-ray images were obtained with the Advanced CCD Imaging Spectrometer-S (ACIS-S) instrument on the [*Chandra*]{} X-ray Observatory on 2002 May 22, showing a 0.2–10.0 keV luminosity of [$\sim\!\!$ ]{}$10^{38}$ [ergs s$^{-1}$]{} [@Schlegel02]. [SN 2001ig]{}was also detected at radio frequencies; for further information on the radio data and analysis, see @Ryder04. Here we 