OGLE-2019-BLG-0825 : constraints on the source system and effect on binary-lens parameters arising from a five day xallarap effect in a candidate planetary microlensing event
Abstract
We present an analysis of microlensing event OGLE-2019-BLG-0825. This event was identified as a planetary candidate by preliminary modeling. We find that significant residuals from the best-fit static binary-lens model exist and a xallarap effect can fit the residuals very well and significantly improves χ2 values. On the other hand, by including the xallarap effect in our models, we find that binary-lens parameters like mass-ratio, q, and separation, s, cannot be constrained well. However, we also find that the parameters for the source system like the orbital period and semi major axis are consistent between all the models we analyzed. We therefore constrain the properties of the source system better than the properties of the lens system. The source system comprises a G-type main-sequence star orbited by a brown dwarf with a period of P ∼ 5 days. This analysis is the first to demonstrate that the xallarap effect does affect binary-lens parameters in planetary events. It would not be common for the presence or absence of the xallarap effect to affect lens parameters in events with long orbital periods of the source system or events with transits to caustics, but in other cases, such as this event, the xallarap effect can affect binary-lens parameters.
Citation
Satoh , Y K , Koshimoto , N , Bennett , D P , Sumi , T , Rattenbury , N J , Suzuki , D , Miyazaki , S , Bond , I A , Udalski , A , Gould , A , Bozza , V , Dominik , M , Hirao , Y , Kondo , I , Kirikawa , R , Hamada , R , Abe , F , Barry , R , Bhattacharya , A , Fujii , H , Fukui , A , Fujita , K , Ikeno , T , Ishitani Silva , S , Itow , Y , Matsubara , Y , Matsumoto , S , Muraki , Y , Niwa , K , Okamura , A , Olmschenk , G , Ranc , C , Toda , T , Tomoyoshi , M , Tristram , P J , Vandorou , A , Yama , H , Yamashita , K , Mróz , P , Poleski , R , Skowron , J , Szymański , M K , Poleski , R , Soszyński , I , Pietrukowicz , P , Kozłowski , S , Ulaczyk , K , Rybicki , K A , Iwanek , P , Wrona , M , Gromadzki , M , Albrow , M D , Chung , S-J , Han , C , Hwang , K-H , Kim , D , Jung , Y K , Kim , H W , Ryu , Y-H , Shin , I-G , Shvartzvald , Y , Yang , H , Yee , J C , Zang , W , Cha , S-M , Kim , D-J , Kim , S-L , Lee , C-U , Lee , D-J , Lee , Y , Park , B-G , Pogge , R W , Jørgensen , U G , Longa-Peña , P , Sajadian , S , Skottfelt , J , Snodgrass , C , Tregloan-Reed , J , Bach-Møller , N , Burgdorf , M , D'Ago , G , Haikala , L , Hitchcock , J , Hundertmark , M , Khalouei , E , Peixinho , N , Rahvar , S , Southworth , J & Spyratos , P 2023 , ' OGLE-2019-BLG-0825 : constraints on the source system and effect on binary-lens parameters arising from a five day xallarap effect in a candidate planetary microlensing event ' , Astronomical Journal , vol. 166 , no. 3 , 116 . https://doi.org/10.3847/1538-3881/ace908
Publication
Astronomical Journal
Status
Peer reviewed
ISSN
0004-6256Type
Journal article
Description
Funding: The MOA project is supported by JSPS KAKENHI Grant Number JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, and JP17H02871. Y.S. acknowledges support from BSF Grant No. 2020740. J.C.Y. acknowledges support from U.S. NSF Grant No. AST-2108414. U.G.J., N.B-M. and J.S. acknowledge funding from the European Union H2020-MSCA-ITN-2019 under Grant Number 860470 (CHAMELEON), from the Novo Nordisk Foundation Interdisciplinary Synergy Program Grant Number NNF19OC0057374 and from the Carlsberg Foundation under Grant Number CF18-0552. N.P.’s work was supported by Fundação para a Ciência e a Tecnologia (FCT) through the research grants UIDB/04434/2020 and UIDP/04434/2020. P.L.P. was partly funded by “Programa de Iniciación en Investigación-Universidad de Antofagasta INI-17-03”. G.D. acknowledges support by ANID, BASAL, FB210003.Collections
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