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 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.
Authors
- Thiam-Guan Tan (ORCID: https://orcid.org/0000-0001-5603-6895)
- I. B. Thompson (ORCID: https://orcid.org/0000-0001-5130-6040)
- M. Subroweit (ORCID: https://orcid.org/0000-0001-6165-8525)
- C. Straubmeier (ORCID: https://orcid.org/0000-0002-0671-9302)
- Jonas Sauter
- S. Lacour (ORCID: https://orcid.org/0000-0002-6948-0263)
- Sven Buder (ORCID: https://orcid.org/0000-0002-4031-8553)
- S. Robbe-Dubois
- D. C. Ribeiro (ORCID: https://orcid.org/0000-0001-9990-7312)
- M. Houllé (ORCID: https://orcid.org/0000-0001-5633-2010)
- C. Dougados (ORCID: https://orcid.org/0000-0001-6660-936X)
- A. Drescher (ORCID: https://orcid.org/0000-0002-4494-5503)
- Joss Bland‐Hawthorn (ORCID: https://orcid.org/0000-0001-7516-4016)
- Jean-Philippe Berger (ORCID: https://orcid.org/0000-0001-5025-0428)
- Romain Laugier (ORCID: https://orcid.org/0000-0002-2215-9413)
- J. Shangguan (ORCID: https://orcid.org/0000-0002-4569-9009)
- Pierre-Olivier Petrucci (ORCID: https://orcid.org/0000-0001-6061-3480)
- F. Widmann (ORCID: https://orcid.org/0000-0002-0327-6585)
- Laura Kreidberg (ORCID: https://orcid.org/0000-0003-0514-1147)
- Subo Dong (ORCID: https://orcid.org/0000-0002-1027-0990)
- R. Davies (ORCID: https://orcid.org/0000-0003-4949-7217)
- R. Genzel (ORCID: https://orcid.org/0000-0002-2767-9653)
- C. S. Kochanek (ORCID: https://orcid.org/0000-0001-6017-2961)
- Sanjib Sharma (ORCID: https://orcid.org/0000-0002-0920-809X)
- Felix Mang
- Janez Kos (ORCID: https://orcid.org/0000-0003-2533-6056)
- T. Paumard (ORCID: https://orcid.org/0000-0003-0655-0452)
- H. Nowacki (ORCID: https://orcid.org/0000-0002-5762-0249)
- Denis Defrère (ORCID: https://orcid.org/0000-0003-3499-2506)
- C. Sykes (ORCID: https://orcid.org/0000-0003-3819-3023)
- G. Heißel (ORCID: https://orcid.org/0000-0003-4965-856X)
- Grant Christie (ORCID: https://orcid.org/0000-0003-2342-4271)
- A. Eckart (ORCID: https://orcid.org/0000-0001-6049-3132)
- A. Mérand (ORCID: https://orcid.org/0000-0003-2125-0183)
- T. Natusch (ORCID: https://orcid.org/0000-0002-1354-7510)
- G. Perrin (ORCID: https://orcid.org/0000-0003-0680-0167)
- Maximilian Fabricius (ORCID: https://orcid.org/0000-0002-7025-6058)
- D. Lutz (ORCID: https://orcid.org/0000-0003-0291-9582)
- D. A. H. Buckley (ORCID: https://orcid.org/0000-0002-7004-9956)
- A. Udalski (ORCID: https://orcid.org/0000-0001-5207-5619)
- E. Sturm (ORCID: https://orcid.org/0000-0002-0018-3666)
- Julien M. Woillez (ORCID: https://orcid.org/0000-0002-2958-4738)
- R. Petrov (ORCID: https://orcid.org/0000-0003-4759-6051)
- H. Feuchtgruber
- Thomas Shimizu (ORCID: https://orcid.org/0000-0002-2125-4670)
- N. Pourré
- Olivier Lai (ORCID: https://orcid.org/0000-0001-5656-7346)
- J. Leftley (ORCID: https://orcid.org/0000-0001-6009-1803)
- P. Mróz (ORCID: https://orcid.org/0000-0001-7016-1692)
- F. Millour (ORCID: https://orcid.org/0000-0002-9765-7783)
- S. Gillessen (ORCID: https://orcid.org/0000-0002-5708-0481)
- Guillaume Bourdarot (ORCID: https://orcid.org/0000-0002-6777-6386)
- P. Kervella (ORCID: https://orcid.org/0000-0003-0626-1749)
- J.-B. Le Bouquin (ORCID: https://orcid.org/0000-0002-0493-4674)
- W. Brandner (ORCID: https://orcid.org/0000-0003-1939-6351)
- T. Bensby (ORCID: https://orcid.org/0000-0003-3978-1409)
- P. García (ORCID: https://orcid.org/0000-0002-1678-3535)
- L. J. Tacconi (ORCID: https://orcid.org/0000-0002-1485-9401)
- Thomas Ott (ORCID: https://orcid.org/0000-0003-1572-0396)
- N. M. Förster Schreiber (ORCID: https://orcid.org/0000-0003-4264-3381)
- M. Montargès (ORCID: https://orcid.org/0000-0002-7540-999X)
- K. Abd El Dayem
- Zexuan Wu (ORCID: https://orcid.org/0009-0007-5754-6206)
- Frédéric E. Vincent (ORCID: https://orcid.org/0000-0002-3855-0708)
- Bruno Lopez
- Karine Perraut
- Frank Eisenhauer
- M. Sadun Bordoni
- Jules Scigliuto
- S. F. Hönig
- Anthony Berdeu
- Mathias Nowak
- S. Rabien
- Andrew Gould
- Daryl Santos (ORCID: https://orcid.org/0009-0004-6445-3022)
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2024-12-01
- DOI
- https://doi.org/10.3847/1538-4357/ad90b9
- Citations
- 4
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 1.33
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- California Institute of Technology
- European Space Agency
- National Natural Science Foundation of China
- Narodowym Centrum Nauki
- European Southern Observatory