  Abstract We investigate a short-period W UMa binary KIC 9026766 with an
orbital period of 0.2721278 days in the Kepler field of view. By using an
automated q-search for the folded light curve and producing a synthetic light
curve for this object based on the PHOEBE code, we calculate the fundamental
stellar parameters. We also analyze the O-C curve of the primary minima. The
orbital period changes can be attributed to the combination of an upward
quadratic function and light-travel time effect due to a possible third body
with a minimum mass of 0.029 solar mass and an orbital period of 972.5866 days.
The relative luminosity of the primary and secondary eclipses (Min I Min II) is
calculated. The periodogram of the residuals of the LTT effect, and Min I Min
II show peaks with the same period of 0.8566 days. The background effect of two
nearby stars on our target is the possible reason for this signal. By
considering the amplitudes and periods of the remaining signals in the OC curve
of minima, spot motion is possible.
