MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary

E. Bachelet; Y. Tsapras; Andrew Gould; R. A. Street; David P. Bennett; M. P. G. Hundertmark; V. Bozza; D. M. Bramich; A. Cassan; M. Dominik; K. Horne; S. Mao; A. Saha; J. Wambsganss; Weicheng Zang; Fumio Abe; Richard Barry; Aparna Bhattacharya; Ian A. Bond; Akihiko Fukui; Hirosane Fujii; Yuki Hirao; Yoshitaka Itow; Rintaro Kirikawa; Iona Kondo; Naoki Koshimoto; Yutaka Matsubara; Sho Matsumoto; Shota Miyazaki; Yasushi Muraki; Greg Olmschenk; Clément Ranc; Arisa Okamura; Nicholas J. Rattenbury; Yuki Satoh; Takahiro Sumi; Daisuke Suzuki; Stela Ishitani Silva; Taiga Toda; Paul . J. Tristram; Aikaterini Vandorou; Hibiki Yama; Michael D. Albrow; Sun-Ju Chung; Cheongho Han; Kyu-Ha Hwang; Youn Kil Jung; Yoon-Hyun Ryu; In-Gu Shin; Yossi Shvartzvald; Jennifer C. Yee; Sang-Mok Cha; Dong-Jin Kim; Seung-Lee Kim; Chung-Uk Lee; Dong-Joo Lee; Yongseok Lee; Byeong-Gon Park; Richard W. Pogge; Andrzej Udalski; Przemek Mróz; Radosław Poleski; Jan Skowron; Michał K. Szymański; Igor Soszyński; Paweł Pietrukowicz; Szymon Kozłowski; Krzysztof Ulaczyk; Krzysztof A. Rybicki; Patryk Iwanek; Marcin Wrona; Mariusz Gromadzki

doi:10.3847/1538-3881/ac78ed

MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary

E. Bachelet^*
, Y. Tsapras
, Andrew Gould
, R. A. Street
, David P. Bennett
, M. P. G. Hundertmark
, V. Bozza
, D. M. Bramich
, A. Cassan
, M. Dominik
, K. Horne
, S. Mao
, A. Saha
, J. Wambsganss
, Weicheng Zang
, Fumio Abe
, Richard Barry
, Aparna Bhattacharya
, Ian A. Bond
, Akihiko Fukui

Hirosane Fujii, Yuki Hirao, Yoshitaka Itow, Rintaro Kirikawa, Iona Kondo, Naoki Koshimoto, Yutaka Matsubara, Sho Matsumoto, Shota Miyazaki, Yasushi Muraki, Greg Olmschenk, Clément Ranc, Arisa Okamura, Nicholas J. Rattenbury, Yuki Satoh, Takahiro Sumi, Daisuke Suzuki, Stela Ishitani Silva, Taiga Toda, Paul . J. Tristram, Aikaterini Vandorou, Hibiki Yama, Michael D. Albrow, Sun-Ju Chung, Cheongho Han, Kyu-Ha Hwang, Youn Kil Jung, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Jennifer C. Yee, Sang-Mok Cha, Dong-Jin Kim, Seung-Lee Kim, Chung-Uk Lee, Dong-Joo Lee, Yongseok Lee, Byeong-Gon Park, Richard W. Pogge, Andrzej Udalski, Przemek Mróz, Radosław Poleski, Jan Skowron, Michał K. Szymański, Igor Soszyński, Paweł Pietrukowicz, Szymon Kozłowski, Krzysztof Ulaczyk, Krzysztof A. Rybicki, Patryk Iwanek, Marcin Wrona, Mariusz Gromadzki

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

We report on the observations, analysis and interpretation of the microlensing event MOA-2019-BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not cross caustics and no finite-source effects were observed. Therefore, the angular Einstein ring radius θ_E cannot be measured from the light curve alone. However, the large event duration, t_E ∼ 80 days, allows a precise measurement of the microlensing parallax π_E. In addition to the constraints on the angular radius θ_* and the apparent brightness I_s of the source, we employ the Besançon and GalMod galactic models to estimate the physical properties of the lens. We find excellent agreement between the predictions of the two galactic models: the companion is likely a resident of the brown dwarf desert with a mass M_p ∼ 30 M_Jup, and the host is a main-sequence dwarf star. The lens lies along the line of sight to the Galactic bulge, at a distance of ≤4 kpc. We estimate that in about 10 yr the lens and source will be separated by ∼55 mas, and it will be possible to confirm the exact nature of the lensing system by using high-resolution imaging from ground- or space-based observatories.

Original language	English
Article number	75
Journal	Astronomical Journal
Volume	164
Issue number	3
Early online date	2 Aug 2022
DOIs	https://doi.org/10.3847/1538-3881/ac78ed
Publication status	Published - 1 Sept 2022

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Bachelet-2022-MOA-2019-BLG-008Lb-AJ-164-3-75-CCBY
Copyright © 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
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https://arxiv.org/abs/2205.07522

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Astronomy at St Andrews 2018-2021: Astronomy at St Andrews 2018-2021
Jardine, M. (PI), Bonnell, I. (CoI), Cameron, A. (CoI), Cyganowski, C. (CoI), Dominik, M. (CoI), Helling, C. (CoI), Horne, K. (CoI), Scholz, A. (CoI), Tojeiro, R. (CoI), Weijmans, A.-M. (CoI), Wild, V. (CoI), Woitke, P. (CoI), Wood, K. (CoI) & Zhao, H. (CoI)
1/04/18 → 31/03/22
Project: Standard

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Bachelet, E., Tsapras, Y., Gould, A., Street, R. A., Bennett, D. P., Hundertmark, M. P. G., Bozza, V., Bramich, D. M., Cassan, A., Dominik, M., Horne, K., Mao, S., Saha, A., Wambsganss, J., Zang, W., Abe, F., Barry, R., Bhattacharya, A., Bond, I. A., ... Gromadzki, M. (2022). MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary. Astronomical Journal, 164(3), Article 75. https://doi.org/10.3847/1538-3881/ac78ed

@article{87ae335cce6540e4bce074854027d52b,

title = "MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary",

abstract = "We report on the observations, analysis and interpretation of the microlensing event MOA-2019-BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not cross caustics and no finite-source effects were observed. Therefore, the angular Einstein ring radius θE cannot be measured from the light curve alone. However, the large event duration, tE ∼ 80 days, allows a precise measurement of the microlensing parallax πE. In addition to the constraints on the angular radius θ* and the apparent brightness Is of the source, we employ the Besan{\c c}on and GalMod galactic models to estimate the physical properties of the lens. We find excellent agreement between the predictions of the two galactic models: the companion is likely a resident of the brown dwarf desert with a mass Mp ∼ 30 MJup, and the host is a main-sequence dwarf star. The lens lies along the line of sight to the Galactic bulge, at a distance of ≤4 kpc. We estimate that in about 10 yr the lens and source will be separated by ∼55 mas, and it will be possible to confirm the exact nature of the lensing system by using high-resolution imaging from ground- or space-based observatories.",

author = "E. Bachelet and Y. Tsapras and Andrew Gould and Street, \{R. A.\} and Bennett, \{David P.\} and Hundertmark, \{M. P. G.\} and V. Bozza and Bramich, \{D. M.\} and A. Cassan and M. Dominik and K. Horne and S. Mao and A. Saha and J. Wambsganss and Weicheng Zang and Fumio Abe and Richard Barry and Aparna Bhattacharya and Bond, \{Ian A.\} and Akihiko Fukui and Hirosane Fujii and Yuki Hirao and Yoshitaka Itow and Rintaro Kirikawa and Iona Kondo and Naoki Koshimoto and Yutaka Matsubara and Sho Matsumoto and Shota Miyazaki and Yasushi Muraki and Greg Olmschenk and Cl{\'e}ment Ranc and Arisa Okamura and Rattenbury, \{Nicholas J.\} and Yuki Satoh and Takahiro Sumi and Daisuke Suzuki and Silva, \{Stela Ishitani\} and Taiga Toda and Tristram, \{Paul . J.\} and Aikaterini Vandorou and Hibiki Yama and Albrow, \{Michael D.\} and Sun-Ju Chung and Cheongho Han and Kyu-Ha Hwang and Jung, \{Youn Kil\} and Yoon-Hyun Ryu and In-Gu Shin and Yossi Shvartzvald and Yee, \{Jennifer C.\} and Sang-Mok Cha and Dong-Jin Kim and Seung-Lee Kim and Chung-Uk Lee and Dong-Joo Lee and Yongseok Lee and Byeong-Gon Park and Pogge, \{Richard W.\} and Andrzej Udalski and Przemek Mr{\'o}z and Rados{\l}aw Poleski and Jan Skowron and Szyma{\'n}ski, \{Micha{\l} K.\} and Igor Soszy{\'n}ski and Pawe{\l} Pietrukowicz and Szymon Koz{\l}owski and Krzysztof Ulaczyk and Rybicki, \{Krzysztof A.\} and Patryk Iwanek and Marcin Wrona and Mariusz Gromadzki",

note = "Funding: R.A.S. and E.B. gratefully acknowledge support from NASA grant 80NSSC19K0291. Y.T. and J.W. acknowledge the support of DFG priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (WA 1047/11-1). K.H. acknowledges support from STFC grant ST/R000824/1. J.C.Y. acknowledges support from NSF grant No. AST-2108414. Work by C.H. was supported by the grants of the National Research Foundation of Korea (2019R1A2C2085965 and 2020R1A4A2002885). D.M.B. acknowledges the support of the NYU Abu Dhabi Research Enhancement Fund under grant RE124. This work was partly supported by the National Science Foundation of China (grant Nos. 11333003, 11390372, and 11761131004 to S.M.). The MOA project is supported by JSPS KAKENHI grant Nos. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, and JP17H02871. ",

year = "2022",

month = sep,

day = "1",

doi = "10.3847/1538-3881/ac78ed",

language = "English",

volume = "164",

journal = "Astronomical Journal",

issn = "0004-6256",

publisher = "American Astronomical Society",

number = "3",

}

Bachelet, E, Tsapras, Y, Gould, A, Street, RA, Bennett, DP, Hundertmark, MPG, Bozza, V, Bramich, DM, Cassan, A, Dominik, M , Horne, K, Mao, S, Saha, A, Wambsganss, J, Zang, W, Abe, F, Barry, R, Bhattacharya, A, Bond, IA, Fukui, A, Fujii, H, Hirao, Y, Itow, Y, Kirikawa, R, Kondo, I, Koshimoto, N, Matsubara, Y, Matsumoto, S, Miyazaki, S, Muraki, Y, Olmschenk, G, Ranc, C, Okamura, A, Rattenbury, NJ, Satoh, Y, Sumi, T, Suzuki, D, Silva, SI, Toda, T, Tristram, PJ, Vandorou, A, Yama, H, Albrow, MD, Chung, S-J, Han, C, Hwang, K-H, Jung, YK, Ryu, Y-H, Shin, I-G, Shvartzvald, Y, Yee, JC, Cha, S-M, Kim, D-J, Kim, S-L, Lee, C-U, Lee, D-J, Lee, Y, Park, B-G, Pogge, RW, Udalski, A, Mróz, P, Poleski, R, Skowron, J, Szymański, MK, Soszyński, I, Pietrukowicz, P, Kozłowski, S, Ulaczyk, K, Rybicki, KA, Iwanek, P, Wrona, M & Gromadzki, M 2022, 'MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary', Astronomical Journal, vol. 164, no. 3, 75. https://doi.org/10.3847/1538-3881/ac78ed

TY - JOUR

T1 - MOA-2019-BLG-008Lb

T2 - a new microlensing detection of an object at the planet/brown dwarf boundary

AU - Bachelet, E.

AU - Tsapras, Y.

AU - Gould, Andrew

AU - Street, R. A.

AU - Bennett, David P.

AU - Hundertmark, M. P. G.

AU - Bozza, V.

AU - Bramich, D. M.

AU - Cassan, A.

AU - Dominik, M.

AU - Horne, K.

AU - Mao, S.

AU - Saha, A.

AU - Wambsganss, J.

AU - Zang, Weicheng

AU - Abe, Fumio

AU - Barry, Richard

AU - Bhattacharya, Aparna

AU - Bond, Ian A.

AU - Fukui, Akihiko

AU - Fujii, Hirosane

AU - Hirao, Yuki

AU - Itow, Yoshitaka

AU - Kirikawa, Rintaro

AU - Kondo, Iona

AU - Koshimoto, Naoki

AU - Matsubara, Yutaka

AU - Matsumoto, Sho

AU - Miyazaki, Shota

AU - Muraki, Yasushi

AU - Olmschenk, Greg

AU - Ranc, Clément

AU - Okamura, Arisa

AU - Rattenbury, Nicholas J.

AU - Satoh, Yuki

AU - Sumi, Takahiro

AU - Suzuki, Daisuke

AU - Silva, Stela Ishitani

AU - Toda, Taiga

AU - Tristram, Paul . J.

AU - Vandorou, Aikaterini

AU - Yama, Hibiki

AU - Albrow, Michael D.

AU - Chung, Sun-Ju

AU - Han, Cheongho

AU - Hwang, Kyu-Ha

AU - Jung, Youn Kil

AU - Ryu, Yoon-Hyun

AU - Shin, In-Gu

AU - Shvartzvald, Yossi

AU - Yee, Jennifer C.

AU - Cha, Sang-Mok

AU - Kim, Dong-Jin

AU - Kim, Seung-Lee

AU - Lee, Chung-Uk

AU - Lee, Dong-Joo

AU - Lee, Yongseok

AU - Park, Byeong-Gon

AU - Pogge, Richard W.

AU - Udalski, Andrzej

AU - Mróz, Przemek

AU - Poleski, Radosław

AU - Skowron, Jan

AU - Szymański, Michał K.

AU - Soszyński, Igor

AU - Pietrukowicz, Paweł

AU - Kozłowski, Szymon

AU - Ulaczyk, Krzysztof

AU - Rybicki, Krzysztof A.

AU - Iwanek, Patryk

AU - Wrona, Marcin

AU - Gromadzki, Mariusz

N1 - Funding: R.A.S. and E.B. gratefully acknowledge support from NASA grant 80NSSC19K0291. Y.T. and J.W. acknowledge the support of DFG priority program SPP 1992 “Exploring the Diversity of Extrasolar Planets” (WA 1047/11-1). K.H. acknowledges support from STFC grant ST/R000824/1. J.C.Y. acknowledges support from NSF grant No. AST-2108414. Work by C.H. was supported by the grants of the National Research Foundation of Korea (2019R1A2C2085965 and 2020R1A4A2002885). D.M.B. acknowledges the support of the NYU Abu Dhabi Research Enhancement Fund under grant RE124. This work was partly supported by the National Science Foundation of China (grant Nos. 11333003, 11390372, and 11761131004 to S.M.). The MOA project is supported by JSPS KAKENHI grant Nos. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, and JP17H02871.

PY - 2022/9/1

Y1 - 2022/9/1

N2 - We report on the observations, analysis and interpretation of the microlensing event MOA-2019-BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not cross caustics and no finite-source effects were observed. Therefore, the angular Einstein ring radius θE cannot be measured from the light curve alone. However, the large event duration, tE ∼ 80 days, allows a precise measurement of the microlensing parallax πE. In addition to the constraints on the angular radius θ* and the apparent brightness Is of the source, we employ the Besançon and GalMod galactic models to estimate the physical properties of the lens. We find excellent agreement between the predictions of the two galactic models: the companion is likely a resident of the brown dwarf desert with a mass Mp ∼ 30 MJup, and the host is a main-sequence dwarf star. The lens lies along the line of sight to the Galactic bulge, at a distance of ≤4 kpc. We estimate that in about 10 yr the lens and source will be separated by ∼55 mas, and it will be possible to confirm the exact nature of the lensing system by using high-resolution imaging from ground- or space-based observatories.

AB - We report on the observations, analysis and interpretation of the microlensing event MOA-2019-BLG-008. The observed anomaly in the photometric light curve is best described through a binary lens model. In this model, the source did not cross caustics and no finite-source effects were observed. Therefore, the angular Einstein ring radius θE cannot be measured from the light curve alone. However, the large event duration, tE ∼ 80 days, allows a precise measurement of the microlensing parallax πE. In addition to the constraints on the angular radius θ* and the apparent brightness Is of the source, we employ the Besançon and GalMod galactic models to estimate the physical properties of the lens. We find excellent agreement between the predictions of the two galactic models: the companion is likely a resident of the brown dwarf desert with a mass Mp ∼ 30 MJup, and the host is a main-sequence dwarf star. The lens lies along the line of sight to the Galactic bulge, at a distance of ≤4 kpc. We estimate that in about 10 yr the lens and source will be separated by ∼55 mas, and it will be possible to confirm the exact nature of the lensing system by using high-resolution imaging from ground- or space-based observatories.

U2 - 10.3847/1538-3881/ac78ed

DO - 10.3847/1538-3881/ac78ed

M3 - Article

SN - 0004-6256

VL - 164

JO - Astronomical Journal

JF - Astronomical Journal

IS - 3

M1 - 75

ER -

MOA-2019-BLG-008Lb: a new microlensing detection of an object at the planet/brown dwarf boundary

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