Interstellar Lines and Diffuse Bands in the Spectrum of the Supergiant Cas

We have studied the interstellar lines and diffuse bands in the spectrum of the supergiant Cas using the CCD spectra obtained with the Echelle spectrograph of the 2 meter telescope at the peak Terskol observatory. A synthetic stellar spectrum was used to correctly reveal the interstellar features, computed for a model atmosphere with T-eff = 21 500 K, log g = 2.60, v sin i = 83 kms(-1), [M/H] = 0.0, = 15 kms(-1) and with partial selection of main chemical element abundances. Eleven interstellar bands and 91 diffuse interstellar bands were identified. A further 14 absorption features were revealed, possibly also diffuse bands. The spectrophotometric diffuse band parameters and their accuracies were tabulated. We present maps of observed and synthetic spectral regions containing interstellar diffuse bands.