Simulations of Triple Microlensing Events I: Detectability of a scaled Sun-Jupiter-Saturn System

• DOI: 10.48550/arxiv.2211.13393
• Publication Date: 2023-02-10
• Authors: Renkun Kuang; Weicheng Zang; Shude Mao; Jiyuan Zhang; Haochang Jiang
• Keywords: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); 0103 physical sciences; FOS: Physical sciences; Astrophysics - Astrophysics of Galaxies; 01 natural sciences; Astrophysics - Earth and Planetary Astrophysics

ABSTRACTUp to date, only 13 firmly established triple microlensing events have been discovered, so the occurrence rates of microlensing two-planet systems and planets in binary systems are still uncertain. With the upcoming space-based microlensing surveys, hundreds of triple microlensing events will be detected. To provide clues for future observations and statistical analyses, we initiate a project to investigate the detectability of triple-lens systems with different configurations and observational set-ups. As the first step, in this work we develop the simulation software and investigate the detectability of a scaled Sun–Jupiter–Saturn system with the recently proposed telescope for microlensing observations on the ‘Earth 2.0 (ET)’ satellite. With the same Δχ2 thresholds of detecting a single planet and two planets, we find that the detectability of the scaled Sun-Jupiter-Saturn analogue is about 1 per cent and the presence of the Jovian planet suppresses the detectability of the Saturn-like planet by ∼13 per cent regardless of the adopted detection Δχ2 threshold. This suppression probability could be at the same level as the Poisson noise of future space-based statistical samples of triple-lenses, so it is inappropriate to treat each planet separately during detection efficiency calculations.