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Title: First Resolution of Microlensed Images of a Binary-lens Event
Abstract We resolve the multiple images of the binary-lens microlensing event ASASSN-22av using the GRAVITY instrument of the Very Large Telescope Interferometer (VLTI). The light curves show weak binary-lens perturbations, complicating the analysis, but the joint modeling with the VLTI data breaks several degeneracies, arriving at a strongly favored solution. Thanks to precise measurements of the angular Einstein radiusθE= 0.724 ± 0.002 mas and microlens parallax, we determine that the lens system consists of two M dwarfs with masses ofM1= 0.258 ± 0.008M⊙andM2= 0.130 ± 0.007M⊙, a projected separation ofr⊥= 6.83 ± 0.31 au, and a distance ofDL= 2.29 ± 0.08 kpc. The successful VLTI observations of ASASSN-22av open up a new path for studying intermediate-separation (i.e., a few astronomical units) stellar-mass binaries, including those containing dark compact objects such as neutron stars and stellar-mass black holes.  more » « less
Award ID(s):
2307385
PAR ID:
10628098
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more » ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Corporate Creator(s):
Publisher / Repository:
AAS Journals
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
977
Issue:
2
ISSN:
0004-637X
Page Range / eLocation ID:
229
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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