Princeton University Astroplasmas Seminar

Tidal capture of a white dwarf (WD) by a stellar-mass compact object occurs due to close encounters (with periastron separation of a few WD radii) in dense stellar clusters as well as in triple systems. We consider the subsequent evolution of the binary system after the tidal capture, under the influence of dynamical tides and gravitational waves (GWs). We find that the post-capture orbit rapidly shrinks to an eccentricity of about 0.9 in about 10 years as a result of diffusive growth of the amplitude of the prograde f-mode oscillation. Afterwards, the mode amplitude stops growing diffusively, and the orbital decay is dominated by GW emission with a merger time of a few kyr. The observational appearance of the system in the GW and electromagnetic sky will be discussed.