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Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc

Rybicki, K. A. and Wyrzykowski, Ł. and Bachelet, E. and Cassan, A. and Zieliński, P. and Gould, A. and Calchi Novati, S. and Yee, J. C. and Ryu, Y.-H. and Gromadzki, M. and Mikołajczak, M. and Ihanec, N. and Kruszyńska, K. and Hambsch, F.-J. and Zola, S. and Fossey, S. J. and Awiphan, S. and Nakharutai, N. and Lewis, F. and Olivares E., F. and Hodgkin, S. and Delgado, A. and Breedt, E. and Harrison, D. L. and van Leeuwen, M. and Rixon, G. and Wevers, T. and Yoldas, A. and Udalski, A. and Szymański, M. K. and Soszyński, I. and Pietrukowicz, P. and Kozlowski, S. and Skowron, J. and Poleski, R. and Ulaczyk, K. and Mróz, P. and Iwanek, P. and Wrona, M. and Street, R. A. and Tsapras, Y. and Hundertmark, M. and Dominik, M. and Beichman, C. A. and Bryden, G. and Carey, S. and Gaudi, B. S. and Henderson, C. and Shvartzvald, Y. and Zang, W. and Zhu, W. and Christie, G. W. and Green, J. and Hennerley, S. and McCormick, J. and Monard, L. A. G. and Natusch, T. and Pogge, R. W. and Gezer, I. and Gurgul, A. and Kaczmarek, Z. and Konacki, M. and Lam, M. C. and Maskoliunas, M. and Pakstiene, E. and Ratajczak, M. and Stankeviciute, A. and Zdanavicius, J. and Ziółkowska, O. (2022) Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc. Astronomy and Astrophysics, 657 . Art. No. A18. ISSN 0004-6361. doi:10.1051/0004-6361/202039542.

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Context. Microlensing provides a unique opportunity to detect non-luminous objects. In the rare cases that the Einstein radius θ_E and microlensing parallax π_E can be measured, it is possible to determine the mass of the lens. With technological advances in both ground- and space-based observatories, astrometric and interferometric measurements are becoming viable, which can lead to the more routine determination of θ_E and, if the microlensing parallax is also measured, the mass of the lens. Aims. We present the photometric analysis of Gaia19bld, a high-magnification (A ≈ 60) microlensing event located in the southern Galactic plane, which exhibited finite source and microlensing parallax effects. Due to a prompt detection by the Gaia satellite and the very high brightness of I = 9.05 mag at the peak, it was possible to collect a complete and unique set of multi-channel follow-up observations, which allowed us to determine all parameters vital for the characterisation of the lens and the source in the microlensing event. Methods. Gaia19bld was discovered by the Gaia satellite and was subsequently intensively followed up with a network of ground-based observatories and the Spitzer Space Telescope. We collected multiple high-resolution spectra with Very Large Telescope (VLT)/X-shooter to characterise the source star. The event was also observed with VLT Interferometer (VLTI)/PIONIER during the peak. Here we focus on the photometric observations and model the light curve composed of data from Gaia, Spitzer, and multiple optical, ground-based observatories. We find the best-fitting solution with parallax and finite source effects. We derived the limit on the luminosity of the lens based on the blended light model and spectroscopic distance. Results. We compute the mass of the lens to be 1.13 ± 0.03 M_⊙ and derive its distance to be 5.52_(−0.64)^(+0.35) kpc. The lens is likely a main sequence star, however its true nature has yet to be verified by future high-resolution observations. Our results are consistent with interferometric measurements of the angular Einstein radius, emphasising that interferometry can be a new channel for determining the masses of objects that would otherwise remain undetectable, including stellar-mass black holes.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Rybicki, K. A.0000-0002-9326-9329
Calchi Novati, S.0000-0002-7669-1069
Gromadzki, M.0000-0002-1650-1518
Zola, S.0000-0003-3609-382X
Olivares E., F.0000-0002-5115-6377
Breedt, E.0000-0001-6180-3438
Harrison, D. L.0000-0001-8687-6588
van Leeuwen, M.0000-0002-5222-4888
Wevers, T.0000-0002-4043-9400
Udalski, A.0000-0001-5207-5619
Szymański, M. K.0000-0002-0548-8995
Soszyński, I.0000-0002-7777-0842
Pietrukowicz, P.0000-0002-2339-5899
Kozlowski, S.0000-0003-4084-880X
Skowron, J.0000-0002-2335-1730
Poleski, R.0000-0002-9245-6368
Ulaczyk, K.0000-0001-6364-408X
Mróz, P.0000-0001-7016-1692
Iwanek, P.0000-0002-6212-7221
Wrona, M.0000-0002-3051-274X
Street, R. A.0000-0001-6279-0552
Tsapras, Y.0000-0001-8411-351X
Dominik, M.0000-0002-3202-0343
Beichman, C. A.0000-0002-5627-5471
Bryden, G.0000-0001-5966-837X
Carey, S.0000-0002-0221-6871
Gaudi, B. S.0000-0003-0395-9869
Henderson, C.0000-0001-8877-9060
Shvartzvald, Y.0000-0003-1525-5041
Zang, W.0000-0001-6000-3463
Pogge, R. W.0000-0003-1435-3053
Kaczmarek, Z.0000-0002-4887-3121
Ratajczak, M.0000-0002-3218-2684
Additional Information:© ESO 2021. Received: 28 September 2020 Accepted: 20 July 2021. The authors would like to thank the referee for their comments, which helped improving the quality of the paper. This work was supported from the Polish NCN grants: Preludium No. 2017/25/N/ST9/01253, Harmonia No. 2018/30/M/ST9/00311, MNiSW grant DIR/WK/2018/12, Daina No. 2017/27/L/ST9/03221, and by the Research Council of Lithuania, grant No. S-LL-19-2. The OGLE project has received funding from the NCN grant MAESTRO 2014/14/A/ST9/00121 to AU. We acknowledge the European Commission’s H2020 OPTICON grant No. 730890. YT acknowledges the support of DFG priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (WA 1047/11-1). EB and RS gratefully acknowledge support from NASA grant 80NSSC19K0291. Work by AG was supported by JPL grant 1500811. Work by JCY was supported by JPL grant 1571564. SJF thanks Telescope Live for access to their telescope network. NN acknowledges the support of Data Science Research Center, Chiang Mai University. FOE acknowledges the support from the FONDECYT grant nr. 1201223. MK acknowledges the support from the NCN grant No. 2017/27/B/ST9/02727.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
National Science Centre (Poland)2017/25/N/ST9/01253
National Science Centre (Poland)2018/30/M/ST9/00311
Ministerstwo Nauki i Szkolnictwa Wyższego (MNiSW)DIR/WK/2018/12
National Science Centre (Poland)2017/27/L/ST9/03221
Research Council of LithuaniaS-LL-19-2
National Science Centre (Poland)2014/14/A/ST9/00121
European Research Council (ERC)730890
Deutsche Forschungsgemeinschaft (DFG)WA 1047/11-1
Chiang Mai UniversityUNSPECIFIED
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1201223
National Science Centre (Poland)2017/27/B/ST9/02727
Subject Keywords:gravitational lensing: micro / stars: fundamental parameters / white dwarfs / stars: neutron
Record Number:CaltechAUTHORS:20211221-473340000
Persistent URL:
Official Citation:Single-lens mass measurement in the high-magnification microlensing event Gaia19bld located in the Galactic disc K. A. Rybicki, Ł. Wyrzykowski, E. Bachelet, A. Cassan, P. Zieliński, A. Gould, S. Calchi Novati, J. C. Yee, Y.-H. Ryu, M. Gromadzki, P. Mikołajczyk, N. Ihanec, K. Kruszyńska, F.-J. Hambsch, S. Zoła, S. J. Fossey, S. Awiphan, N. Nakharutai, F. Lewis, F. Olivares E., S. Hodgkin, A. Delgado, E. Breedt, D. L. Harrison, M. van Leeuwen, G. Rixon, T. Wevers, A. Yoldas, A. Udalski, M. K. Szymański, I. Soszyński, P. Pietrukowicz, S. Kozłowski, J. Skowron, R. Poleski, K. Ulaczyk, P. Mróz, P. Iwanek, M. Wrona, R. A. Street, Y. Tsapras, M. Hundertmark, M. Dominik, C. Beichman, G. Bryden, S. Carey, B. S. Gaudi, C. Henderson, Y. Shvartzvald, W. Zang, W. Zhu, G. W. Christie, J. Green, S. Hennerley, J. McCormick, L. A. G. Monard, T. Natusch, R. W. Pogge, I. Gezer, A. Gurgul, Z. Kaczmarek, M. Konacki, M. C. Lam, M. Maskoliunas, E. Pakstiene, M. Ratajczak, A. Stankeviciute, J. Zdanavicius and O. Ziółkowska A&A, 657 (2022) A18 DOI:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:112611
Deposited By: George Porter
Deposited On:21 Dec 2021 21:41
Last Modified:08 Aug 2022 20:46

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