The Component Star Masses in RW Tri

We use time-resolved spectra of the cataclysmic variable RW Tri in the I and Kband to determine the orbital velocity of the secondary star using skew mapping and cross correlation techniques respectively. We find radial velocity amplitudes of 250±47 km/s in the I-band, and 221±29 km/s in the K-band. We also determine the rotational velocity of the secondary star using the K-band data and find a Vrot sin i of 120 ± 20km/s. A combination of these results coupled with an estimate of the effect of heating on the secondary star suggests a mass ratio M2/M1 in the range 0.6− 1.1; the mass ratio range with no correction for heating is 0.5 − 0.8. These lead to most likely estimates of the primary and secondary star masses in the range 0.4 − 0.7M⊙ and 0.3−0.4M⊙ respectively. Further refinement of the stellar masses is hampered by uncertain knowledge of the white dwarf orbital velocity, and we discuss evidence that at least some estimates of the white dwarf velocity are contaminated by non-orbital components.