Identifying disappearance of a white dwarf binary with LISA

We discuss the prospect of identifying a white dwarf binary merger by monitoring disappearance of its nearly monochromatic gravitational wave. For a 10 yr operation of the laser interferometer space antenna (LISA), the chance probability of observing such an event is roughly estimated to be 20 per cent. By simply using short-term coherent signal integrations, we might determine the merger time with an accuracy of similar to 3-10 d. Also considering its expected sky localizability similar to 0.1-0.01 deg(2), LISA might make an interesting contribution to the multimessenger study on a merger event.