The Latest Spectral Peregrinations of Rx-Puppis

Abstract

We present centimetre- and millimetre-wave continuum measurements of the symbiotic binary system RX Puppis. These suggest that RX Pup has returned to a state of low excitation after more than a decade of activity. Although the overall optical brightness has not altered substantially during the past two years, recent low-resolution ultraviolet and optical spectroscopy demonstrates that the system has undergone a dramatic transformation. The data are discussed in the context of a popular model in which highly variable mass loss from a compact star interacts with the wind of a distant Mira to cause the observed periods of low and high excitation. We go on to introduce a rival scenario in which material is gravitationally stripped from the Mira by a compact companion with an accretion disc. The disc meets comparatively recent requirements for a method of collimating mass loss from the compact star. Finally, we mention several methods with the capability to discriminate between the competing models.