Observations of Microlensed Images with Dual-field Interferometry: On-sky Demonstration and Prospects
Abstract Interferometric observations of gravitational microlensing events offer an opportunity for precise, efficient, and direct mass and distance measurements of lensing objects, especially those of isolated neutron stars and black holes. However, such observations have previously been possible for only a handful of extremely bright events. The recent development of a dual-field interferometer, GRAVITY Wide, has made it possible to reach out to significantly fainter objects and increase the pool of microlensing events amenable to interferometric observations by 2 orders of magnitude. Here, we present the first successful observation of a microlensing event with GRAVITY Wide and the resolution of microlensed images in the event OGLE-2023-BLG-0061/KMT-2023-BLG-0496. We measure the angular Einstein radius of the lens with subpercent precision, θ E = 1.280 ± 0.009 mas. Combined with the microlensing parallax detected from the event light curve, the mass and distance to the lens are found to be 0.472 ± 0.012 M ⊙ and 1.81 ± 0.05 kpc, respectively. We present the procedure for the selection of targets for interferometric observations and discuss possible systematic effects affecting GRAVITY Wide data. This detection demonstrates the capabilities of the new instrument, and it opens up completely new possibilities for the follow-up of microlensing events and future routine discoveries of isolated neutron stars and black holes.
Authors
- Sang-Mok Cha (ORCID: https://orcid.org/0000-0002-7511-2950)
- M. Subroweit (ORCID: https://orcid.org/0000-0001-6165-8525)
- Yongseok Lee (ORCID: https://orcid.org/0000-0001-7594-8072)
- I. Soszyński (ORCID: https://orcid.org/0000-0002-7777-0842)
- Michael D. Albrow (ORCID: https://orcid.org/0000-0003-3316-4012)
- C. Straubmeier (ORCID: https://orcid.org/0000-0002-0671-9302)
- Weicheng Zang (ORCID: https://orcid.org/0000-0001-6000-3463)
- Hongjing Yang (ORCID: https://orcid.org/0000-0003-0626-8465)
- Jonas Sauter
- S. Hoenig (ORCID: https://orcid.org/0000-0002-6353-1111)
- A. Drescher (ORCID: https://orcid.org/0000-0002-4494-5503)
- M. Gromadzki (ORCID: https://orcid.org/0000-0002-1650-1518)
- Kyu‐Ha Hwang (ORCID: https://orcid.org/0000-0002-9241-4117)
- J. Shangguan (ORCID: https://orcid.org/0000-0002-4569-9009)
- 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)
- Krzysztof A. Rybicki (ORCID: https://orcid.org/0000-0002-9326-9329)
- R. Genzel (ORCID: https://orcid.org/0000-0002-2767-9653)
- M. K. Szymański (ORCID: https://orcid.org/0000-0002-0548-8995)
- J. Skowron (ORCID: https://orcid.org/0000-0002-2335-1730)
- Byeong-Gon Park (ORCID: https://orcid.org/0000-0002-6982-7722)
- R. Poleski (ORCID: https://orcid.org/0000-0002-9245-6368)
- Yoon-Hyun Ryu (ORCID: https://orcid.org/0000-0001-9823-2907)
- Zhuokai Liu
- T. Paumard (ORCID: https://orcid.org/0000-0003-0655-0452)
- Denis Defrère (ORCID: https://orcid.org/0000-0003-3499-2506)
- Yossi Shvartzvald (ORCID: https://orcid.org/0000-0003-1525-5041)
- Seung‐Lee Kim (ORCID: https://orcid.org/0000-0003-0562-5643)
- Chung‐Uk Lee (ORCID: https://orcid.org/0000-0003-0043-3925)
- Dong-Joo Lee (ORCID: https://orcid.org/0009-0000-5737-0908)
- Sun‐Ju Chung (ORCID: https://orcid.org/0000-0001-6285-4528)
- Cheongho Han (ORCID: https://orcid.org/0000-0002-2641-9964)
- A. Mérand (ORCID: https://orcid.org/0000-0003-2125-0183)
- Maximilian Fabricius (ORCID: https://orcid.org/0000-0002-7025-6058)
- D. Lutz (ORCID: https://orcid.org/0000-0003-0291-9582)
- A. Udalski (ORCID: https://orcid.org/0000-0001-5207-5619)
- Julien M. Woillez (ORCID: https://orcid.org/0000-0002-2958-4738)
- Youn Kil Jung (ORCID: https://orcid.org/0000-0002-0314-6000)
- Thomas Shimizu (ORCID: https://orcid.org/0000-0002-2125-4670)
- Patryk Iwanek (ORCID: https://orcid.org/0000-0002-6212-7221)
- P. Pietrukowicz (ORCID: https://orcid.org/0000-0002-2339-5899)
- 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)
- K. Ulaczyk (ORCID: https://orcid.org/0000-0001-6364-408X)
- Guillaume Bourdarot (ORCID: https://orcid.org/0000-0002-6777-6386)
- In-Gu Shin (ORCID: https://orcid.org/0000-0002-4355-9838)
- J.-B. Le Bouquin (ORCID: https://orcid.org/0000-0002-0493-4674)
- Jennifer C. Yee (ORCID: https://orcid.org/0000-0001-9481-7123)
- S. Kozłowski (ORCID: https://orcid.org/0000-0003-4084-880X)
- Richard W. Pogge (ORCID: https://orcid.org/0000-0003-1435-3053)
- P. García (ORCID: https://orcid.org/0000-0002-1678-3535)
- Thomas Ott (ORCID: https://orcid.org/0000-0003-1572-0396)
- Marcin Wrona (ORCID: https://orcid.org/0000-0002-3051-274X)
- Mateusz J. Mróz (ORCID: https://orcid.org/0000-0002-8911-6581)
- Dongjin Kim (ORCID: https://orcid.org/0000-0003-3562-0384)
- Zexuan Wu (ORCID: https://orcid.org/0009-0007-5754-6206)
- Frank Eisenhauer
- Andrew Gould
Publication Details
- Journal
- The Astrophysical Journal
- Published
- 2025-02-03
- DOI
- https://doi.org/10.3847/1538-4357/ad9b14
- Citations
- 3
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 3.46
Funders
- National Science Foundation
- Smithsonian Institution
- United States - Israel Binational Science Foundation
- University of Southampton
- European Commission
- National Research Foundation
- National Natural Science Foundation of China
- Korea Astronomy and Space Science Institute
- National Research Foundation of Korea
- KU Leuven
- Narodowe Centrum Nauki
- Narodowym Centrum Nauki
- European Southern Observatory
- Centre National de la Recherche Scientifique
- Universität zu Köln
- Ministry of Science and ICT, South Korea
- Korea Research Environment Open Network
- Max-Planck-Institut für Astronomie
- Smithsonian Astrophysical Observatory
- Observatoire de Paris, Université de Recherche Paris Sciences et Lettres