LAUSR

We study the anomalous mass defects in the first (ascendant) branch of stellar sequences of static strange stars. We employ the nonperturbative equation of state derived in the framework of the Field Correlator Method to describe the hydrostatic equilibrium of the strange matter. The large distance static $q{\bar q}$ potential $V_1$ and the gluon condensate $G_2$ are the model parameters that characterize the equation of state. An attempt is made to determine, from the surface gravitational redshift measurements, the ratio $({\cal P}/{\cal E})_C$ at the center of strange stars. For $V_1=0$ and $G_2\gappr0.035\,{\rm GeV}^4$\,, it is shown that $({\cal P}/{\cal E})_C\simeq0.262$ and the corresponding redshift $z_S\simeq0.47$ are limiting values, at the maximum mass of the stellar sequence . As a direct application of our study, we try to determine the values of $V_1$ and $G_2$ from astrophysical observations of the compact star 1E1207.4-5209. After two attempts to obtain the model parameters, our findings show that $V_1=0.44\pm0.10$\,GeV and $G_2=0.008\pm0.001\,{\rm GeV}^4$\, in the first attempt and $V_1=0.43\pm0.085$\,GeV and $G_2=0.0093\pm0.00092\,{\rm GeV}^4$ in the second attempt. The corresponding ratios $({\cal P}/{\cal E})_C$ are $0.073^{+0.029}_{+0.024}$ and $0.087\pm0.028$\,, respectively. As a consequence of these high values of the model parameters, the respective anomalous mass defect of 1E1207.4-5209 are $|\Delta_2M|\simeq2.56\times10^{53}$\,erg\, and $|\Delta_2M|\simeq2.94\times10^{53}$\,erg\,.