Vito Saggese (U. Naples): "Hunting Triple Exoplanetary Systems with the Roman Space Telescope"

Gravitational microlensing is a powerful technique for exoplanet detection, offering unbiased sensitivity to planets at or beyond the snow line. However, so far only a limited number of multi-planetary systems have been discovered using this method. This leads to a crucial question: how effectively can next-generation observatories detect these multi-planetary systems? To investigate this, we utilized VBMicrolensing, a numerical tool designed to model magnification in complex lensing configurations, including triple-lens systems and beyond. Our simulations indicate that the Roman Space Telescope could detect triple-lens planetary systems in approximately 60% of instances where the source trajectory passes near the central caustic. These results highlight Roman's potential to systematically investigate multi-planetary systems through microlensing, providing essential insights into their frequency, architecture and formation processes.