In a recent study , Armstrong et al .
presented an eclipsing binary star of about 6.2 h period with transit-like tertiary signals occurring every 204.2 d in the Kepler public data of KIC002856960 and proposed three possible hierarchical structures : ( AB ) b , ( AB ) C , and A ( BC ) .
We analyzed the Kepler light curve by including a third light source and one starspot on each binary component .
The results represent that the close eclipsing pair is in a low-mass eccentric-orbit , detached configuration .
Based on 123 eclipse timings calculated from the Wilson-Devinney binary model , a period study of the close binary reveals that the orbital period has experienced a sinusoidal variation with a period and a semi-amplitude of 205 \pm 2 d and 0.0021 \pm 0.0002 d , respectively .
The period variation would be produced by the light-travel-time effect due to a gravitationally-bound third body with a minimum mass of M _ { 3 } \sin i _ { 3 } =0.76 M _ { \odot } in an eccentric orbit of e _ { 3 } =0.61 .
This is consistent with the presence of third light found in our light-curve solution and the tertiary signal of 204.2 d period most likely arises from the K-type star crossed by the close eclipsing binary .
Then , KIC002856960 is a triply eclipsing hierarchical system , A ( BC ) , consisting of a close binary with two M-type dwarfs and a more massive K-type component .
The presence of the third star may have played an important role in the formation and evolution of the close pair , which may ultimately evolve into a contact system by angular momentum loss .