Abstract

Contributed Talk - Plenary

Gravitational Microlensing in the Era of Gaia DR4

Mauritz Wicker
University of Warsaw & Isaac Newton Group of Telescopes

Gravitational microlensing offers a unique window into compact objects and otherwise unseen mass in the Galaxy through photometric and astrometric observations. The Gaia mission has delivered high-precision, time-resolved measurements of microlensing events across the entire sky. In this talk, I will discuss Gaia’s capabilities for detecting and characterizing microlensing events, with particular emphasis on the complementary roles of photometric light curves and astrometric centroid shifts. I will outline what can be expected from Gaia Data Release 4, planned for December 2026, including improved time series, extended baselines, and enhanced sensitivity to long-duration and high-mass lenses. Finally, I will present a detailed analysis of a notable event, Gaia20fnr, illustrating the scientific potential of Gaia microlensing in combination with photometric follow-up observations.