First Resolution of Microlensed Images of a Binary-lens Event
Wu, Z. ; Bensby, T. LU
and Widmann, F.
(2024)
In Astrophysical Journal
977(2).
- 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 radius θ E = 0.724 ± 0.002 mas and microlens parallax, we determine that the lens system consists of two M dwarfs with masses of M 1 = 0.258 ± 0.008 M ⊙ and M 2 = 0.130 ± 0.007 M ⊙, a projected separation of r ⊥ = 6.83 ± 0.31 au, and a distance of D L = 2.29 ± 0.08 kpc. The successful VLTI observations of ASASSN-22av open up a new path... (More)
- 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 radius θ E = 0.724 ± 0.002 mas and microlens parallax, we determine that the lens system consists of two M dwarfs with masses of M 1 = 0.258 ± 0.008 M ⊙ and M 2 = 0.130 ± 0.007 M ⊙, a projected separation of r ⊥ = 6.83 ± 0.31 au, and a distance of D L = 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. © 2024. The Author(s). Published by the American Astronomical Society. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8ed9b16a-18de-4987-bf63-3bbc10bec2e7
- author
- Wu, Z.
; Bensby, T.
LU
and Widmann, F.
- author collaboration
- organization
- publishing date
- 2024
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Astrophysical Journal
- volume
- 977
- issue
- 2
- article number
- 229
- publisher
- American Astronomical Society
- external identifiers
-
- scopus:85212575268
- ISSN
- 0004-637X
- DOI
- 10.3847/1538-4357/ad90b9
- language
- English
- LU publication?
- yes
- id
- 8ed9b16a-18de-4987-bf63-3bbc10bec2e7
- date added to LUP
- 2025-11-21 12:35:34
- date last changed
- 2025-11-21 12:36:49
@article{8ed9b16a-18de-4987-bf63-3bbc10bec2e7,
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 radius θ E = 0.724 ± 0.002 mas and microlens parallax, we determine that the lens system consists of two M dwarfs with masses of M 1 = 0.258 ± 0.008 M ⊙ and M 2 = 0.130 ± 0.007 M ⊙, a projected separation of r ⊥ = 6.83 ± 0.31 au, and a distance of D L = 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. © 2024. The Author(s). Published by the American Astronomical Society.}},
author = {{Wu, Z. and Bensby, T. and Widmann, F.}},
issn = {{0004-637X}},
language = {{eng}},
number = {{2}},
publisher = {{American Astronomical Society}},
series = {{Astrophysical Journal}},
title = {{First Resolution of Microlensed Images of a Binary-lens Event}},
url = {{http://dx.doi.org/10.3847/1538-4357/ad90b9}},
doi = {{10.3847/1538-4357/ad90b9}},
volume = {{977}},
year = {{2024}},
}