In this contribution I will present recent results on the study of symbiotic stars, interacting systems in which a white dwarf accretes material from an evolved (typically a RGB or AGB) star. The very high luminosity and intrinsic variability of evolved stars complicates the identification and study of symbiotic stars. However, X-ray emission is a distinctive feature that opens a window to...
The mechanism for X-ray generation in the Gamma Cas analogues, a small group of highly variable Oe/Be stars, has been a mystery for several decades. They are characterised by their hard X-ray spectra, often including strong Fe fluorescence lines, and X-ray luminosities in the gap between those seen in similar stars and the more luminous Be/X-ray Binaries. They have also been observed to be...
V2487 Oph is a recurrent nova that underwent a fast and luminous eruption in 1998 (t₃ ≈ 8 days, peak magnitude 9.5). The host system hosts a massive white dwarf (~1.35 M☉) accreting from a donor star (~0.21 M☉) in a binary with an orbital period of 0.753 days (~18.1 hours). Previous X-ray observations conducted 2.7 and 3.2 years after the outburst suggested that accretion had resumed in the...
Accreting magnetic white dwarfs offer a unique window into accretion physics in binary systems. Like X-ray binaries, they harbour a standard Shakura-Sunyaev accretion disc whose inner edge can be magnetically truncated, yet their lower energies and longer dynamical timescales make the inner accretion geometry far more accessible. I will present results on DW Cnc, a well-studied intermediate...
The mass of a white dwarf (WD) is a fundamental parameter for understanding its formation, evolution, and role in binary systems. A large fraction of WDs are found in interacting binaries known as Cataclysmic Variables (CVs), where the WD accretes material from a low-mass donor star, typically a late-type main-sequence star. The X-ray emission from a class of magnetic CVs called the...
