Discovery of Metastable Helium Absorption Lines in V1280 Scorpii

We report on the discovery of blue-shifted metastable He I* absorption lines at 3188 ˚ A and 3889 ˚ A with multiple components on high-resolution spectra (R � 60000) of V1280 Scorpii. Similar multiple absorption lines associated with the Na I D doublet as well as Ca II H and K were observed. Na I D doublet absorption lines have been observed since 2009, while the metastable He I* absorption lines were absent in 2009, but were detected in 2011 (four years after the burst). We have found different time variations in the depths and velocities of blue-shifted absorption components among He I* ,N aI, and Ca II. The complex time evolutions of these lines can be explained by assuming changes in the density and recombination/ionization rate when the ejecta expands and the photosphere contracts to become hotter. The multiple absorption lines originate in ejected materials consisting of clumpy components, which obscure a significant part of the continuum emitting region. We estimate the total mass of the ejected material to be on the order of � 10 � 4 Mˇ, using metastable He I* �� 3188 and 3889 absorption lines.