The symbiotic binary system RX Puppis: a possible recurrent nova with a Mira companion

Abstract

A B S T R A C TWe present an analysis of photometric and spectroscopic observations of the symbiotic binary system RX Pup with the aim of developing a reliable binary model for the system and identifying mechanisms responsible for its spectacular activity. The binary is composed of a long-period Mira variable surrounded by a thick dust shell and a hot ,0:8 M ( white dwarf companion. The hot component produces practically all activity observed in the UV, optical and radio range, while variable obscuration of the Mira by circumstellar dust is responsible for long-term changes in the near-infrared magnitudes. The observations show that RX Pup underwent a nova-like eruption during the last three decades. The hot component contracted in radius at roughly constant luminosity from 1975 to 1986, and was the source of a strong stellar wind, which prevented it from accreting material lost in the Mira wind. Around 1988/9 the hot component turned over in the Hertzsprung±Russell (HR) diagram and by 1991 its luminosity had faded by a factor of ,30 with respect to the maximum plateau value and the hot wind had practically ceased. By 1995 the nova remnant started to accrete material from the Mira wind, as indicated by a general increase in intensity of the optical continuum and H i emission. The quiescent spectrum resembles the quiescent spectra of symbiotic recurrent novae, and its intensity indicates that the hot component must accrete as much as ,1 per cent of the Mira wind, which is more or less the amount predicted by Bondi±Hoyle theory. The earliest observational records from the 1890s suggest that another nova-like eruption of RX Pup occurred around 1894.

The influence of binarity on dust obscuration events in the planetary nebula M 2-29 and its analogues

“…Perhaps least understood are those variables that exhibit fading events due to dust obscuration. These include R Coronae Borealis stars (RCB, Clayton 1996), Population-I WC9 stars (Veen et al 1998;Kato et al 2002), symbiotic stars (Mikołajewska et al 1999;Mennickent et al 2008;Gromadzki et al 2009), PNe (Méndez et al 1982;Cohen et al 2002;Hajduk et al 2008, hereafter HZG08) stars with long secondary periods or LSPs (Wood et al 1999(Wood et al , 2004Soszyński 2007;Nicholls et al 2009;). …”

A catalogue of symbiotic stars

“…092=RT Ser IRAS data from [142]. [147] 016 UV Aur Max(mpg) = 2441062 395.42 [147] 026 RX Pup Min(J) = 2440214 578 [202] 029 KM Vel ? 370 [75] 030 V366 Car ?…”

The ongoing outburst of the new symbiotic star IPHASJ190832.31+051226.6

“…One example is V4368 Sgr (=Wakuda's peculiar variable; Munari et al 2009b) that took no less than four years to reach the optical maximum and where the amplitude in the red largely exceeded the one displayed (so far) by IPHAS J190832.31+051226.6. Other examples are V1329 Cyg, in which the system took 7 years to get to its maximum visual luminosity (Munari et al 1988), and RX Pup (10 years, Mikolajewska et al 1999). IPHAS J190832.31+051226.6 seems to have a luminosity development similar to these symbiotic novae, but the sparse photometric data available so far do not allow us to precisely determine the structure of the outburst and to disentangle it from secular changes.…”