HIGH-RESOLUTION SPECTROSCOPY OF R-CRB - PULSATIONS, SHELLS AND MASS-LOSS

High spectral resolution observations obtained in 1994 and spanning th ree pulsation cycles of R CrB are discussed along with available UBV p hotometric observations for the same epochs. Model atmosphere based an alyses of the spectra at pulsation light maximum and minimum show the atmosphere to be cooler by 500 K at minimum. Radial velocities of high - and low-excitation lines at maximum light show, on one occasion, a m arked velocity difference. Weak blueshifted H alpha emission is seen i n spectra at the phase of minimum light. In addition to a photospheric component, the NaI D lines show absorption components from circumstel lar gas. One strong component not seen in 1990 or early 1993 may be a result of gas ejected during the late-1933 deep decline.