A model for the outburst of nova RS Ophiuchi in 1985

The radio and X-ray emission of the 1985 outburst of the recurrent nova RS Oph are discussed in terms of a spherically symmetric model in which high-velocity ejecta interact with a slow moving pre-outburst wind. Consideration of the free–free optical depth at radio frequencies in the overlying wind, together with the observed X-ray luminosity and shock temperature, lead us to conclude that the remnant was in transition between phase II and phase III at the time of the X-ray observations. If so it is possible to construct a consistent model of the development of the remnant if metals are overabundant and there are density enhancements in the wind. It is proposed that inhomogeneities in density are produced in regions of magnetic field line reconnection in the azimuthal field of the wind. If the early radio emission is non-thermal, then we calculate that the total energy content of relativistic electrons is approximately 0.02 per cent of the total energy of the remnant. The total energy in the nova explosion is estimated to be $$8\times{10}^{42}$$ erg.