  V752 Cen is a triple-lined spectroscopic contact binary. Its multi-color
light curves were obtained in the years 1971 and 2018, independently.
Photometric analyses reveal that the two sets of light curves produce almost
consistent results. It contains a W-subtype totally eclipsing binary, and its
mass ratio and fill-out factor are $q = 3.35(1)$ and $f = 29(2)\,\%$. The
absolute elements of its two component stars were determined to be $M_{1} =
0.39(2)M_\odot$, $M_{2} = 1.31(7)M_\odot$, $R_{1} = 0.77(1)R_\odot$, $R_{2} =
1.30(2)R_\odot$, $L_{1} = 0.75(3)L_\odot$ and $L_{2} = 2.00(7)L_\odot$. The
period of V752 Cen is 0.37023198 day. The 0.37-d period remained constant from
its first measurement in 1971 until the year 2000. However, it changed suddenly
around the year 2000 and has been increasing continuously at a rate of
$dP/dt=+5.05\times{10^{-7}}day\cdot year^{-1}$ since then, which can be
explained by mass transfer from the less massive component star to the more
massive one with a rate of $\frac{dM_{2}}{dt}=2.52\times{10^{-7}}M_\odot/year$.
The period variation of V752 Cen over the 48 years in which the period has been
monitored is really unusual, and is potentially related to effects from the
possible presence of a nearby third star or of a pair of stars in a second
binary.
