The Instituto de Astrofísica de Canarias (IAC) will host the Gaia Alerts 2025 conference, the 16th Gaia Science Alerts and ACME Time-Domain Workshop, from 29 September to 3 October 2025 at IACTEC in La Laguna (Tenerife). The meeting marks a milestone moment for the Gaia mission, celebrating the end of its science observations, and convenes the international community to chart the next decade of discovery in time-domain and multimessenger astrophysics. 

Time-domain astronomy has rapidly become a cornerstone of modern astrophysics, revealing the dynamic Universe, from stellar explosions and tidal disruption events to the flickering cores of active galaxies and the electromagnetic counterparts of gravitational-wave sources. The workshop will spotlight how integrating observations across the electromagnetic spectrum and beyond, including optical data, gravitational waves, and neutrinos, unlocks new insights into these phenomena and maximizes the scientific return of global alert streams and archives. 

Organized by an international committee chaired by Prof. Łukasz Wyrzykowski (National Centre for Nuclear Research/Astronomical Observatory University of Warsaw, Poland) with co-chairs Dr. Paul Beck (IAC) and Dr. Jaroslav Merc (IAC/Charles University), the meeting will gather experts from time-domain surveys and archives such as Gaia, ZTF, OGLE, and LOFAR, as well as analysts and tool-builders who turn alerts into science. Confirmed invited speakers include researchers from the European Space Agency ESA, the University of Cambridge, the University of Geneva, IAC, and other leading institutions. A hybrid format will enable broad participation, with on-site sessions complemented by online access.

A key focus this year is the BHTOM.space global telescope network, a unique, community-driven infrastructure that coordinates optical follow-up of time-domain events with small and medium-sized telescopes, including facilities in the Canary Islands. Under the Horizon Europe ACME grant, BHTOM is expanding to interface with multimessenger alerts, linking optical, radio, X-ray, UV, gravitational-wave, and neutrino detections, and to ease access to rich time-domain archives for the entire community. 

The programme features morning and early-afternoon sessions throughout the week. On Wednesday, the conference participants will visit the Teide Observatory and the National Park, where experts from the IAC and the University of La Laguna (ULL) will offer the visitors visitors an insight into the scientific infrastructure at the Observatory, the geology of the zone and the pre-hispanic population of Tenerife. On Friday, the final conference day, participants will attend a hackathon, a practical session at the IAC Headquarters dedicated to collaborative development and cross-archive/multimessenger workflows.