We have obtained the first high-dispersion observations of RX Pup in the wavelength region 1200-2000 A with the International Ultraviolet Explorer. RX Pup has been classified a symbiotic star and has been compared to slow novae as well as to 11 Carinae. The anomalies that we observed in high-excitation lines in RX Pup such as He II, 0 III], C III], C IV, and Si IIIl that show split line profiles, Doppler displaced multiple components, and possible inverse P Cygni profiles inN III] and N IV J suggest dynamic activity in circumstellar material that probably has the form of rings and/or gas streamers between the cool giant and the hot companion. The continuum observed by us in low dispersion is fairly flat in the wavelength region 1200-2000 A and rises toward longer wavelengths in the region 2000-3200 A. It cannot be due to a star earlier than AO II. Alternatively it may be from an accretion disk. We find electron densities in the line-emitting region in the range 109-1011 em- 3 , temperatures in the range 10,000-20,000 K, and linear sizes :S a few x 1013 em. We find that the photoionizing radiation may be due to the presence of an unseen, hot subdwarf with most probable effective temperature in the range 75,000-90,000 K. Alternatively it may be due to an accretion disk around a secondary with boundary layer temperature -105 K. Short-range as well as long-range monitoring of this very interesting object in the far-UV would be very helpful in understanding the nature of its peculiar properties and the connection between slow novae and symbiotic stars.
Kafatos, M., Michalitsianos, A.G., Feibelman, W.A. (1982) IUE Observations of the Peculiar Star RX Puppis, Astrophysical Journal, 257: 204-213. doi: 10.1086/159979