Title: GW170817: A gift that keeps on giving

Abstract: GW170817 was detected almost 4 years ago as the first object to have both a gravitational wave and an EM counterpart and provided the first observational confirmation of the connection between short gamma-ray bursts and binary neutron star mergers. It still remains the only one of its kind. For almost 3 years, the evolution of non-thermal emission originating in GW170817 was consistent with an afterglow produced from the interaction of an ultra-relativistic structured jet, that was initially viewed off-axis, with the ambient medium. However, observations after 3.4 years narrated a story different from expectations. We observed a statistically significant excess in X-rays compared to the predictions from a structured jet model, which was not accompanied by an excess in radio. I will discuss our investigation of several theoretical models that could lead to a deviation from the existing model in X-rays only, including the plausibility of an emerging kilonova afterglow, which if true, would make it the first ever to be observed. I will finally discuss the implications of these observations on the nature of the merger remnant.