Four high-resolution spectra taken at VLT/UVES. The spectra have been split in three panels where there is the wavelength gap induced by the dichroic or the detector mosaic (red arm only). Photometric state and age since discovery (in days) are color-coded in the upper panel. The Hα line is saturated in all UVES spectra. The spectra in the figure have not been corrected for reddening.