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OGLE-2019-BLG-0960 Lb: the Smallest Microlensing Planet

Yee, Jennifer C. and Zang, Weicheng and Udalski, Andrzej and Ryu, Yoon-Hyun and Green, Jonathan and Hennerley, Steve and Marmont, Andrew and Sumi, Takahiro and Mao, Shude and Gromadzki, Mariusz and Mróz, Przemek and Skowron, Jan and Poleski, Radoslaw and Szymański, Michał K. and Soszyński, Igor and Pietrukowicz, Paweł and Kozłowski, Szymon and Ulaczyk, Krzysztof and Rybicki, Krzysztof A. and Iwanek, Patryk and Wrona, Marcin and Albrow, Michael D. and Chung, Sun-Ju and Gould, Andrew and Han, Cheongho and Hwang, Kyu-Ha and Jung, Youn Kil and Kim, Hyoun-Woo and Shin, In-Gu and Shvartzvald, Yossi and Cha, Sang-Mok and Kim, Dong-Jin and Kim, Seung-Lee and Lee, Chung-Uk and Lee, Dong-Joo and Lee, Yongseok and Park, Byeong-Gon and Pogge, Richard W. and Bachelet, Etienne and Christie, Grant and Hundertmark, Markus P. G. and Maoz, Dan and McCormick, Jennie and Natusch, Tim and Penny, Matthew T. and Street, Rachel A. and Tsapras, Yiannis and Beichman, Charles A. and Bryden, Geoffery and Calchi Novati, Sebastiano and Carey, Sean and Gaudi, B. Scott and Henderson, Calen B. and Johnson, Samson and Zhu, Wei and Bond, Ian A. and Abe, Fumio and Barry, Richard and Bennett, David P. and Bhattacharya, Aparna and Donachie, Martin and Fujii, Hirosane and Fukui, Akihiko and Hirao, Yuki and Ishitani Silva, Stela and Itow, Yoshitaka and Kirikawa, Rintaro and Kondo, Iona and Koshimoto, Naoki and Li, Man Cheung Alex and Matsubara, Yutaka and Muraki, Yasushi and Miyazaki, Shota and Olmschenk, Greg and Ranc, Clément and Rattenbury, Nicholas J. and Satoh, Yuki and Shoji, Hikaru and Suzuki, Daisuke and Tanaka, Yuzuru and Tristram, Paul J. and Yamawaki, Tsubasa and Yonehara, Atsunori (2021) OGLE-2019-BLG-0960 Lb: the Smallest Microlensing Planet. Astronomical Journal, 162 (5). Art. No. 180. ISSN 0004-6256. doi:10.3847/1538-3881/ac1582.

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We report the analysis of OGLE-2019-BLG-0960, which contains the smallest mass-ratio microlensing planet found to date (q = 1.2–1.6 × 10⁻⁵ at 1σ). Although there is substantial uncertainty in the satellite parallax measured by Spitzer, the measurement of the annual parallax effect combined with the finite source effect allows us to determine the mass of the host star (M_L = 0.3–0.6 M_⊙), the mass of its planet (m_p = 1.4–3.1 M_⊕), the projected separation between the host and planet (a_⊥ = 1.2–2.3 au), and the distance to the lens system (D_L = 0.6–1.2 kpc). The lens is plausibly the blend, which could be checked with adaptive optics observations. As the smallest planet clearly below the break in the mass-ratio function, it demonstrates that current experiments are powerful enough to robustly measure the slope of the mass-ratio function below that break. We find that the cross-section for detecting small planets is maximized for planets with separations just outside of the boundary for resonant caustics and that sensitivity to such planets can be maximized by intensively monitoring events whenever they are magnified by a factor A > 5. Finally, an empirical investigation demonstrates that most planets showing a degeneracy between (s > 1) and (s < 1) solutions are not in the regime |log s| » 0) for which the "close"/"wide" degeneracy was derived. This investigation suggests that there is a link between the "close"/"wide" and "inner/outer" degeneracies and also that the symmetry in the lens equation goes much deeper than symmetries uncovered for the limiting cases.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Yee, Jennifer C.0000-0001-9481-7123
Zang, Weicheng0000-0001-6000-3463
Udalski, Andrzej0000-0001-5207-5619
Ryu, Yoon-Hyun0000-0001-9823-2907
Sumi, Takahiro0000-0002-4035-5012
Mao, Shude0000-0001-8317-2788
Gromadzki, Mariusz0000-0002-1650-1518
Mróz, Przemek0000-0001-7016-1692
Skowron, Jan0000-0002-2335-1730
Poleski, Radoslaw0000-0002-9245-6368
Szymański, Michał K.0000-0002-0548-8995
Soszyński, Igor0000-0002-7777-0842
Pietrukowicz, Paweł0000-0002-2339-5899
Kozłowski, Szymon0000-0003-4084-880X
Ulaczyk, Krzysztof0000-0001-6364-408X
Rybicki, Krzysztof A.0000-0002-9326-9329
Iwanek, Patryk0000-0002-6212-7221
Wrona, Marcin0000-0002-3051-274X
Albrow, Michael D.0000-0003-3316-4012
Chung, Sun-Ju0000-0001-6285-4528
Han, Cheongho0000-0002-2641-9964
Hwang, Kyu-Ha0000-0002-9241-4117
Jung, Youn Kil0000-0002-0314-6000
Kim, Hyoun-Woo0000-0001-8263-1006
Shin, In-Gu0000-0002-4355-9838
Shvartzvald, Yossi0000-0003-1525-5041
Cha, Sang-Mok0000-0002-7511-2950
Kim, Dong-Jin0000-0002-7038-2118
Kim, Seung-Lee0000-0003-0562-5643
Lee, Chung-Uk0000-0003-0043-3925
Lee, Yongseok0000-0001-7594-8072
Park, Byeong-Gon0000-0002-6982-7722
Pogge, Richard W.0000-0003-1435-3053
Bachelet, Etienne0000-0002-6578-5078
Maoz, Dan0000-0002-6579-0483
Penny, Matthew T.0000-0001-7506-5640
Street, Rachel A.0000-0001-6279-0552
Tsapras, Yiannis0000-0001-8411-351X
Beichman, Charles A.0000-0002-5627-5471
Bryden, Geoffery0000-0001-5966-837X
Calchi Novati, Sebastiano0000-0002-7669-1069
Carey, Sean0000-0002-0221-6871
Gaudi, B. Scott0000-0003-0395-9869
Henderson, Calen B.0000-0001-8877-9060
Johnson, Samson0000-0001-9397-4768
Zhu, Wei0000-0003-4027-4711
Barry, Richard0000-0003-4916-0892
Bennett, David P.0000-0001-8043-8413
Fukui, Akihiko0000-0002-4909-5763
Hirao, Yuki0000-0003-4776-8618
Ishitani Silva, Stela0000-0003-2267-1246
Itow, Yoshitaka0000-0002-8198-1968
Kondo, Iona0000-0002-3401-1029
Koshimoto, Naoki0000-0003-2302-9562
Muraki, Yasushi0000-0003-1978-2092
Miyazaki, Shota0000-0001-9818-1513
Olmschenk, Greg0000-0001-8472-2219
Ranc, Clément0000-0003-2388-4534
Rattenbury, Nicholas J.0000-0001-5069-319X
Suzuki, Daisuke0000-0002-5843-9433
Yonehara, Atsunori0000-0003-3480-0973
Alternate Title:OGLE-2019-BLG-0960Lb: The Smallest Microlensing Planet
Additional Information:© 2021. The American Astronomical Society. Received 2020 December 23; revised 2021 July 5; accepted 2021 July 15; published 2021 October 6. Work by J.C.Y. was supported by JPL grant 1571564. W.Z. and S.M. acknowledge support by the National Science Foundation of China (grant No. 11821303 and 11761131004). This research has made use of the KMTNet system operated by the Korea Astronomy and Space Science Institute (KASI) and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. The OGLE has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to AU. This research uses data obtained through the Telescope Access Program (TAP), which has been funded by the National Astronomical Observatories of China, the Chinese Academy of Sciences, and the Special Fund for Astronomy from the Ministry of Finance. The MOA project is supported by JSPS KAKENHI grant No. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, and JP17H02871. This work is based (in part) on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech. Work by AG was supported by AST-1516842 and by JPL grant 1500811. A.G. received support from the European Research Council under the European Unions Seventh Framework Programme (FP 7) ERC grant Agreement No. [321035]. Work by C.H. was supported by the grants of National Research Foundation of Korea (2019R1A2C2085965 and 2020R1A4A2002885). Wei Zhu was supported by the Beatrice and Vincent Tremaine Fellowship at CITA. Y.T. acknowledges the support of DFG priority program SPP 1992 "Exploring the Diversity of Extrasolar Planets" (WA 1047/11-1). This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Based in part on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 179.B-2002.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
National Natural Science Foundation of China11821303
National Natural Science Foundation of China11761131004
National Science Centre (Poland)MAESTRO 2014/14/A/ST9/00121
National Astronomical Observatories of ChinaUNSPECIFIED
Chinese Academy of SciencesUNSPECIFIED
Ministry of Finance (China)UNSPECIFIED
Japan Society for the Promotion of Science (JSPS)JSPS24253004
Japan Society for the Promotion of Science (JSPS)JSPS26247023
Japan Society for the Promotion of Science (JSPS)JSPS23340064
Japan Society for the Promotion of Science (JSPS)JSPS15H00781
Japan Society for the Promotion of Science (JSPS)JP16H06287
Japan Society for the Promotion of Science (JSPS)JP17H02871
European Research Council (ERC)321035
National Research Foundation of Korea2019R1A2C2085965
National Research Foundation of Korea2020R1A4A2002885
Canadian Institute for Theoretical AstrophysicsUNSPECIFIED
Deutsche Forschungsgemeinschaft (DFG)WA 1047/11-1
Subject Keywords:Gravitational microlensing exoplanet detection
Issue or Number:5
Classification Code:Unified Astronomy Thesaurus concepts: Gravitational microlensing exoplanet detection (2147)
Record Number:CaltechAUTHORS:20211014-170548759
Persistent URL:
Official Citation:Jennifer C. Yee et al 2021 AJ 162 180
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111430
Deposited By: George Porter
Deposited On:18 Oct 2021 23:03
Last Modified:08 Aug 2022 20:51

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