1999/06/14 by Cheongho Han, Mun-Suk Chun, Mun‐Suk Chun +1 · 28 citations
Mathematics · Physics and Astronomy · #Adaptive optics and wavefront sensing #Ambiguity #Artificial intelligence #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Binary number #Binary star #Centroid #Computer science #Gravitational lens #Gravitational microlensing #Lens (geology) #Mathematics #Microlens #Optics #Physics #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/307996
published in The Astrophysical Journal 526(1), 405-410 (IOP Publishing) · total 15 pages, including 5 Figures and no Table, submitted to ApJ
arxiv created 1999/06/14 · openalex publication_date 1999/11/20 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In this paper, we study the astrometric properties of gravitational microlensing events caused by binary lenses. By investigating the centroid shifts for various types of binary-lens events, we find that the deviations of the centroid shift trajectories from the elliptical ones of single-lens events are characterized by distortions, twistings, and big jumps. We study the conditions of binary-lens system configurations and source star trajectories for individual types of deviations. We find dramatic differences in the astrometric centroid shifts for binary-lens microlensing events that would be degenerate had their parameters been determined photometrically. Therefore, when additional astrometric observations of a binary-lens event are available, one can resolve the ambiguity of the binary-lens fit and uniquely determine the binary-lens parameters.