Context : GW Virginis stars are a well-studied class of non-radial g -mode pulsators .
SDSS J0349 - 0059 and VV 47 are two PG 1159 stars members of this class of variable stars .
SDSS J0349 - 0059 is an interesting GW Vir star that shows a complete pulsation spectrum , that includes rotational splitting of some of its frequencies .
VV 47 is a pulsating PG 1159 star surrounded by a planetary nebula .
This star is particularly interesting because it exhibits a rich and complex pulsation spectrum .

Aims : We present an asteroseismological study of SDSS J0349 - 0059 and VV 47 aimed mainly at deriving their total mass on the basis of state-of-the-art PG 1159 evolutionary models .

Methods : We compute adiabatic nonradial g -mode pulsation periods for PG 1159 evolutionary models with stellar masses ranging from 0.515 to 0.741 M _ { \sun } , that take into account the complete evolution of the progenitor stars .
We first estimate a mean period spacing for both SDSS J0349 - 0059 and VV 47 , and then we constrain the stellar mass of these stars by comparing the observed period spacing with the asymptotic period spacing and with the average of the computed period spacings .
We also employ the individual observed periods to search for a representative seismological model for each star .
Finally , we estimate the rotation period of SDSS J0349 - 0059 .

Results : We found a spectroscopic mass of M _ { \star } \sim 0.543 M _ { \sun } for SDSS J0349 - 0059 and M _ { \star } \sim 0.529 M _ { \sun } for VV 47 .
By comparing the observed period spacing with the asymptotic period spacing we obtain M _ { \star } \sim 0.569 M _ { \sun } for SDSS J0349 - 0059 and M _ { \star } \sim 0.523 M _ { \sun } for VV 47 .
If we compare the observed period spacing with the average of the computed period spacings we found M _ { \star } \sim 0.535 M _ { \sun } for SDSS J0349 - 0059 and M _ { \star } \sim 0.528 M _ { \sun } for VV 47 .
Searching for the best period fit we found , in the case of SDSS J0349 - 0059 , an asteroseismological model with M _ { \star } = 0.542 M _ { \sun } and T _ { eff } = 91 255 K. For VV 47 , we could not find a unique and unambiguous asteroseismological model .
Finally , for SDSS J0349 - 0059 , we determined the rotation period of SDSS J0349 - 0059 as being P _ { rot } = 1 / \Omega \sim 0.407 days .

Conclusions : The results presented in this work constitute a further step in the study of GW Vir stars through asteroseismology in the frame of fully evolutionary models of PG 1159 stars .
In particular , once again it is shown the potential of asteroseismology to derive stellar masses of PG 1159 stars with an unprecedented precision .