The phases of X-ray emission of RS Oph

The recurrent symbiotic nova RS Oph reoccurred after 21 years on 12 February 2006. In contrast to the 1985 outburst, much denser coverage with X-ray observations was achieved. Swift observed RS Oph up to several times a day while Chandra and XMM-Newton observed two to four times during each phase of evolution. While the Swift observations provide high resolution in time, the Chandra and XMM-Newton observations provide high spectral resolution. Refined models can be constrained by the grating spectra, and interpolation of the model parameters can be constrained by the wealth of Swift observations. We compared the Swift light curve with six X-ray observations taken with EXOSAT during the 1985 outburst. We found that the decay from the supersoft X-ray binary (SSS) phase had been observed.