Institute for Advanced Study/Princeton University Joint Astrophysics Colloquium

With the discovery of a binary neutron star coalescence in gravitational waves, and the discovery of an associated short gamma-ray burst, and the discovery of an associated optical afterglow, we have finally entered the era of gravitational-wave multi-messenger astronomy. We will discuss GW170817, and touch on some of the scientific implications, including confirmation of the kilonova model and estimates for the generation of r-process elements, tests of general relativity, and the first standard siren measurement of the Hubble constant. GW170817 represents a momentous development in gravitational-wave astronomy, and the birth of gravitational-wave cosmology.