  We present the results of our study of X-ray pulsar Cen X-3 using XMM-Newton
observations. The light curve and the spectrum for this observations were built
and Fe triplet within 6.5-7 keV region was detected. The geometric model of
relativistic accretion disk for iron emission lines Fe I K alpha, Fe XXV and Fe
XXVI in 6.4-7.0 keV region was applied. The values of disc inclination, inner
and outer radii of the disc and mass of the central compact object (neutron
star) were obtained. Intensity variations of these lines during orbital motion
were also detected. The largest variation was detected for Fe I K alpha line,
that agrees with the results of other authors. These results conform the model
in which Fe I K alpha line forms in hot plasma of accretion disc and highly
ionized iron lines form in outer regions of binary system. Probably the most
interesting feature of Cen X-3 spectrum is Fe XXV triplet which was found by
Iaria et al. (2005) from Chandra data analysis. We did not find this triplet in
our analysis of XMM-Newton data and explain its absence by the insufficient
energy resolution of XMM-Newton instruments.
