Spiral structure in IP Pegasi: how persistent is it?

We present spectroscopy of the dwarf nova IP Pegasi taken during two consec utive nights, 5 and 6 d after the start of an outburst. Even this late in t he outburst, Doppler maps show marked spiral structure in the accretion dis c, at least as strongly as seen earlier in other outbursts of IP Peg. The s piral shocks are present on both nights with no diminution in strength from one night to the next. The light curves of the lines show an offset to ear lier phases, with the mid-eclipse of the emission lines displaced to phases between -0.015 +/- 0.001 and -0.045 +/- 0.009. This cannot be explained by the presence of the accretion shocks. As well as the fixed spiral pattern, the disc shows strong flaring in the Balmer and He II lambda 4686-Angstrom lines. Irradiation-induced emission is seen from the companion star in the Balmer, He I, He II, Mg II, C II, and other lines. The emission is located near the poles of the companion star, suggesting that the accretion disc s hields the companion star substantially and thus has an effective H/R of or der 0.2 at extreme-ultraviolet (EUV) wavelengths. The Balmer emission is di stinctly broader than the other lines, consistent with non-Doppler broadeni ng.