Spectral evolution of SN 2006au. Days since B_max are reported in the figure. Overall these spectra resemble those of SN 2006V. The narrow emission lines are from the host galaxy. Shown in the inset is the spectrum obtained on 14th March 2006 plotted in the rest frame of the host galaxy, in the wavelength range where narrow Na i D absorption feature has been detected. Over-plotted (red dashed line) is the best fit of two Gaussians with a FWHM of 2.8 Å, from which we obtain a total equivalent width of 0.88 ± 0.11 Å.