%0 Journal Article %T Host Galaxies and the Spectral Variability of Quasars %A Fausto Vagnetti %A Dario Trevese %J Physics %D 2001 %I arXiv %X Brightness variability of QSOs is associated with variations of the spectral energy distribution in the optical-UV range. The observed change of the spectral shape depends on the contribution of the host galaxy. Simulations, taking into account luminosities and spectra expected for the host galaxies, are compared with the observed spectral variability of a complete QSO sample. %U http://arxiv.org/abs/astro-ph/0102252v1