White-light flares on close binaries from Kepler

We identify 234 flare binaries, of which 6818 flares are detected. We compare the flare-binary fraction in different binary morphologies ("detachedness").

The result shows that the fractions in over-contact and ellipsoidal binaries are approximately 10%-20% lower than those in detached and semi-detached systems. We calculate the binary flare activity level (AL) of all the flare binaries, and discuss its variations along the orbital period (P_orb_) and rotation period (P_rot_, calculated for only detached binaries). We find that the AL increases with decreasing P_orb_ or P_rot_, up to the critical values at P_orb_~3 days or P_rot_~1.5 days, and thereafter the AL starts decreasing no matter how fast the stars rotate.