We analyze multicolor light curves and high resolution optical spectroscopy of the eclipsing binary and Double Periodic Variable OGLE 05155332-6925581 .
According to Mennickent et al. , this system shows a significant change in the long non-orbital photometric cycle , a loop in the color-magnitude diagram during this cycle and discrete spectral absorption components that were interpreted as evidence of systemic mass loss .
We find that the best fit to the multi-band light curves requires a circumprimary optically thick disc with a radius about twice the radius of the more massive star .
The spectroscopy indicates a mass ratio of 0.21 \pm 0.02 and masses for the hot and cool stars of 9.1 \pm 0.5 and 1.9 \pm 0.2 M _ { \odot } , respectively .
A comparison with synthetic binary-star evolutionary models indicates that the system has an age of 4.76 \times 10 ^ { 7 } years , is in the phase of rapid mass transfer , the second one in the life of this binary , in a Case-B mass-exchange stage .
Donor-subtracted H \alpha profiles show the presence of double emission formed probably in an optically thin circumstellar medium , while the variable He I profile and the H \beta absorption wings are probably formed in the optically thick circumprimary disc .
The model that best fit the observations shows the system with a relatively large mass transfer rate of \dot { M } = 3.1 \times 10 ^ { -6 } M _ { \odot } /yr .
However , the orbital period remains relatively stable during almost 15 years .
This observation suggests that the hot-spot mass-loss model proposed by other authors is not adequate in this case , and that some other mechanism is efficiently removing angular momentum from the binary .
Furthermore , our observations suggest that the DPV phenomenon could have an important effect in the balance of mass and angular momentum in the system .