We present infrared spectroscopy of the recurrent nova RS Ophiuchi, obtained 11.81, 20.75 and 55.71 d following its 2006 eruption. The spectra are dominated by hydrogen recombination lines, together with He I, O I and O II lines
the electron temperature of ~104 K implied by the recombination spectrum suggests that we are seeing primarily the wind of the red giant, ionized by the ultraviolet flash when RS Oph erupted. However, strong coronal emission lines (i.e. emission from fine structure transitions in ions having high ionization potential) are present in the last spectrum. These imply a temperature of 930 000 K for the coronal gas
this is in line with X-ray observations of the 2006 eruption. The emission linewidths decrease with time in a way that is consistent with the shock model for the X-ray emission. © 2006 The Authors. Journal compilation © 2006 RAS.