Observations of RR Lyrae and X ARIETIS with the IUE satellite.

Abstract

UV spectroscopic observations of RR Lyr and X Ari obtained at high and low dispersion using the LWR and SWP cameras of IUE on Jan. 25-28, 1980, are reported. The data are presented in tables and graphs and compared with the results of synthetic-spectrum calculations based on the VR photometric data of Manduca et al. (1981). Good agreement is obtained for X Ari, but the observed fluxes for RR Lyr are significantly lower than the computed fluxes and (by 0.4 mag at 220 and 240 nm during minimum) than those observed by ANS (Bonnell et al., 1982). This discrepancy is attributed to secondary-cycle (Blazhko) effects and to the fact that line blocking is not taken into account in the synthetic-spectrum computations. The RR Lyr spectrum at the Mg II h and k lines is characterized by no detectable emission and strong interstellar absorption.