4U 1210-64 has been postulated to be a High-Mass X-ray Binary powered by the Be mechanism .
X-ray observations with Suzaku , the ISS Monitor of All-sky X-ray Image ( MAXI ) and the Rossi X-ray Timing Explorer Proportional Counter Array ( PCA ) and All Sky Monitor ( ASM ) provide detailed temporal and spectral information on this poorly understood source .
Long term ASM and MAXI observations show distinct high and low states and the presence of a 6.7101 \pm 0.0005 day modulation , interpreted as the orbital period .
Folded light curves reveal a sharp dip , interpreted as an eclipse .
To determine the nature of the mass donor , the predicted eclipse half-angle was calculated as a function of inclination angle for several stellar spectral types .
The eclipse half-angle is not consistent with a mass donor of spectral type B5 V ; however , stars with spectral types B0 V or B0-5 III are possible .
The best-fit spectral model consists of a power law with index \Gamma =1.85 ^ { +0.04 } _ { -0.05 } and a high-energy cutoff at 5.5 \pm 0.2 keV modified by an absorber that fully covers the source as well as partially covering absorption .
Emission lines from S XVI K \alpha , Fe K \alpha , Fe XXV K \alpha and Fe XXVI K \alpha were observed in the Suzaku spectra .
Out-of-eclipse , Fe K \alpha line flux was strongly correlated with unabsorbed continuum flux , indicating that the Fe I emission is the result of fluorescence of cold dense material near the compact object .
The Fe I feature is not detected during eclipse , further supporting an origin close to the compact object .