TACH, the GCN Upgrade

The Gamma-ray Coordinates Network was built to promptly report the detections of gamma-ray bursts, distributing both machine-readable notices and human-readable circulars. It has become the center distribution point for multimessenger astronomy. TACH, the Time-domain Astrophysics Coordination Hub will modernize GCN (being redefined as the General Coordinates Network) through a switch to Kafka-based streaming, improved interfaces, and improved event archiving. TACH will also broaden GCN’s capabilities, allowing for automated event-based reporting which will collate relevant information from high-energy discovery instruments to enable and aide follow-up observations. These steps will maximize the contribution of high-energy observatories to time-domain, multimessenger science through this decade.