OGLE-2016-BLG-1227L: A Wide-separation Planet from a Very Short-timescale Microlensing Event

被引:17
作者
Han, Cheongho [1 ]
Udalski, Andrzej [2 ]
Gould, Andrew [3 ,4 ]
Albrow, Michael D. [5 ]
Chung, Sun-Ju [6 ,7 ]
Hwang, Kyu-Ha [6 ]
Jung, Youn Kil [6 ]
Lee, Chung-Uk [6 ]
Ryu, Yoon-Hyun [6 ]
Shin, In-Gu [6 ]
Shvartzvald, Yossi [8 ]
Yee, Jennifer C. [9 ]
Zang, Weicheng [10 ,11 ]
Cha, Sang-Mok [6 ,12 ]
Kim, Dong-Jin [6 ]
Kim, Hyoun-Woo [6 ]
Kim, Seung-Lee [6 ,7 ]
Lee, Dong-Joo [6 ]
Lee, Yongseok [6 ,12 ]
Park, Byeong-Gon [6 ,7 ]
Pogge, Richard W. [4 ]
Jee, M. James [13 ,14 ]
Kim, Doeon [1 ]
Kim, Chun-Hwey [15 ]
Kim, Woong-Tae [16 ]
Mroz, Przemek [2 ,17 ]
Szymanski, Michal K. [2 ]
Skowron, Jan [2 ]
Poleski, Radek [2 ,4 ]
Soszynski, Igor [2 ]
Pietrukowicz, Pawel [2 ]
Kozlowski, Szymon [2 ]
Ulaczyk, Krzysztof [18 ]
机构
[1] Chungbuk Natl Univ, Dept Phys, Cheongju 28644, South Korea
[2] Univ Warsaw Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland
[3] Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany
[4] Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA
[5] Univ Canterbury, Dept Phys & Astron, Private Bag 4800, Christchurch 8020, New Zealand
[6] Korea Astron & Space Sci Inst, Daejon 34055, South Korea
[7] Korea Univ Sci & Technol, 217 Gajeong Ro, Daejeon 34113, South Korea
[8] Weizmann Inst Sci, Dept Particle Phys & Astrophys, IL-76100 Rehovot, Israel
[9] Ctr Astrophys Harvard & Smithsonian, 60 Garden St, Cambridge, MA 02138 USA
[10] Tsinghua Univ, Dept Astron, Beijing 100084, Peoples R China
[11] Tsinghua Univ, Tsinghua Ctr Astrophys, Beijing 100084, Peoples R China
[12] Kyung Hee Univ, Sch Space Res, Yongin 17104, Kyeonggi, South Korea
[13] Yonsei Univ, Dept Astron, Seoul, South Korea
[14] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA
[15] Chungbuk Natl Univ, Dept Astron & Space Sci, Cheongju 28644, South Korea
[16] Seoul Natl Univ, Dept Phys & Astron, Seoul 08826, South Korea
[17] CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA
[18] Univ Warwick, Dept Phys, Gibbet Hill Rd, Coventry CV4 7AL, W Midlands, England
基金
新加坡国家研究基金会; 欧洲研究理事会;
关键词
Gravitational lensing; Gravitational microlensing exoplanet detection; MASS FUNCTION; PHOTOMETRY; STARS; SYSTEMS;
D O I
10.3847/1538-3881/ab6a9f
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the analysis of the microlensing event OGLE-2016-BLG-1227. The light curve of this short-duration event appears to be a single-lens event affected by severe finite-source effects. Analysis of the light curve based on a single-lens single-source (1L1S) model yields very small values of the event timescale, <CDATA<i days, and the angular Einstein radius, <CDATA<i mas, making the lens a candidate of a free-floating planet. Close inspection reveals that the 1L1S solution leaves small residuals with an amplitude of Delta I less than or similar to 0.03 mag. We find that the residuals are explained by the existence of an additional widely separated heavier lens component, indicating that the lens is a wide-separation planetary system rather than a free-floating planet. From Bayesian analysis, it is estimated that the planet has a mass of <CDATA<i and it is orbiting a low-mass host star with a mass of <CDATA<i located with a projected separation of <CDATA<i au. The planetary system is located in the Galactic bulge with a line-of-sight separation from the source star of CDATA<i kpc. The event shows that there is a range of deviations in the signatures of host stars for apparently isolated planetary lensing events and that it is possible to identify a host even when a deviation is subtle.
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页数:9
相关论文
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