We present red spectra in the region \sim \lambda 7000–8300Å of the eclipsing dwarf nova IP Peg , with simultaneous narrow-band photometry centered at 7322Å .
We show that by placing a second star on the slit we can correct for the telluric absorption bands which have hitherto made the TiO features from the secondary star unusable .
We use these TiO features to carry out a radial velocity study of the secondary star , and find this gives an improvement in signal-to-noise of a factor two compared with using the NaI doublet .
In contrast with previous results , we find no apparent ellipticity in the radial velocity curve .
As a result we revise the semi-amplitude to K _ { 2 } = 331.3 \pm 5.8 km s ^ { -1 } , and thus the primary and secondary star masses to 1.05 ^ { +0.14 } _ { -0.07 } M _ { \odot } and 0.33 ^ { +0.14 } _ { -0.05 } M _ { \odot } respectively .
Although this is the lowest mass yet derived for the secondary star , it is still over-massive for its observed spectral type .
However , the revised mass and radius bring IP Peg into line with other CVs in the mass-radius-period relationships .

By fitting the phase resolved spectra around the TiO bands to a mean spectrum , we attempt to isolate the lightcurve of the secondary star .
The resulting lightcurve has marked deviations from the expected ellipsoidal shape .
The largest difference is at phase 0.5 , and can be explained as an eclipse of the secondary star by the disc , indicating that the disc is optically thick when viewed at high inclination angles .