Comparison of emission lines in a representative portion of the spectrum from the 2010 Apr. 2 (dash) and 2011 Aug. 21 (solid) observations. Every persistent line was a forbidden transition, e.g. [Fe II] 5412, Fe II 5433 Å; the permitted lines were all systematically significantly weakened or absent in the later spectrum, e.g. Cr II 5407, Fe II 5414, Fe II 5425, Ti II 5421, Fe II 5427 Å. See text for discussion.
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