Some of the Ca I and Ca II lines observed in emission during the outburst phase. The zero velocity is marked by a dotted line. In the Ca II H panel, we also indicate with a dashed line the Fe II 3938.3 Å line (4.81 eV), and note that the redshifted emission may be contaminated by more Fe I and Fe II lines in this wavelength range. For comparison, the quiescence spectrum of 2007 July 30 is displayed. The color code is as in Fig. 5.