Gravitational Wave Alerts: What We Know and When We Know It

Multimessenger observations of compact object mergers are a gold mine (pun intended) for studying nucleosynthesis, cosmology, and the astrophysics of gamma-ray bursts. Astronomers depend upon gravitational-wave (GW), gamma-ray, and neutrino observatories to rapidly deduce, quantify uncertainties in, and communicate the masses, sky positions, and distances of merger candidates. These public alerts are essential to obtaining prompt, well-sampled, multiwavelength electromagnetic observations of counterparts. I will discuss the current state of the art in accuracy and speed of real-time GW analysis; the contents of alerts; the physical, technical, and programmatic limitations; and prospects for future observing runs.