The Unusual Ultraviolet Variability of the QSO 3C 232

Abstract

After examining ultraviolet IUE spectra of 18 QSOs with z greater than 0.35, it is found that one object, 3C 232 (z = 0.533), stands out as exhibiting higly unusual spectral and continuum variability. The H I-Ly-alpha shows at a factor of two decrease in a day. The magnitude of the UV continuum variability is reminiscent of that seen in the optically violent variables at visual wavelengths. Several spectral features at wavelengths shortward of H I-Ly-alpha in the rest frame are identified. A brief discussion comparing the spectrum of 3C 232 with those of other QSOs in our IUE sample at wavelengths shortward of 1216 A is also presented.