A 60-night campaign on dwarf novae - II. Evidence for Balmer emission from the secondary star in IP Peg close to outburst

We present observations of IP Peg obtained during the 1988 International Time Project (see Van Paradijs et al., Paper I). We do not detect any significant emission from the gas stream, but instead we find weak emission in $$\text H\alpha$$ from the secondary star at a level of 2.5 per cent of the total flux, 5 d before a short outburst. We discuss the possibility that the simultaneous detection of Balmer emission from the secondary and a 30 per cent drop in $$\text H\alpha$$ emission may be linked to the outburst mechanism.