MOA-2011-BLG-028Lb : a Neptune-mass microlensing planet in the Galactic bulge
Abstract
We present the discovery of a Neptune-mass planet orbiting a star 0.8 ± 0.3M in the Galactic bulge. The planet manifested itself during the microlensing event MOA-2011-BLG-028/OGLE-2011-BLG-0203 as a low-mass companion to the lens star. The analysis of the light curve provides the measurement of the mass ratio (1.2 ± 0.2) × 10-4 , which indicates that the mass of the planet is 12–60 Earth masses. The lensing system is located at 7.3 ± 0.7 kpc away from the Earth near the direction of Baade's Window. The projected separation of the planet at the time of the microlensing event was 3.1–5.2 au. Although the microlens parallax effect is not detected in the light curve of this event, preventing the actual mass measurement, the uncertainties of mass and distance estimation are narrowed by the measurement of the source star proper motion on the OGLE-III images spanning eight years, and by the low amount of blended light seen, proving that the host star cannot be too bright and massive. We also discuss the inclusion of undetected parallax and orbital motion effects into the models and their influence onto the final physical parameters estimates.preventing the actual mass measurement, the uncertainties of mass and distance estimation are narrowed by the measurement of the source star proper motion on the OGLE-III images spanning eight years, and by the low amount of blended light seen, proving that the host star cannot be too bright and massive. We also discuss the inclusion of undetected parallax and orbital motion effects into the models and their influence onto the final physical parameters estimates.
Citation
Skowron , J , Udalski , A , Poleski , R , Kozłowski , S , Szymański , M K , Wyrzykowski , Ł , Ulaczyk , K , Pietrukowicz , P , Pietrzyński , G , Soszyński , I , Abe , F , Bennett , D P , Bhattacharya , A , Bond , I A , Freeman , M , Fukui , A , Hirao , Y , Itow , Y , Koshimoto , N , Ling , C H , Masuda , K , Matsubara , Y , Muraki , Y , Nagakane , M , Ohnishi , K , Rattenbury , N , Saito , T , Sullivan , D J , Sumi , T , Suzuki , D , Tristram , P J , Yonehara , A , Dominik , M , Jørgensen , U G , Bozza , V , Harpsøe , K , Hundertmark , M & Skottfelt , J 2016 , ' MOA-2011-BLG-028Lb : a Neptune-mass microlensing planet in the Galactic bulge ' , Astrophysical Journal , vol. 820 , no. 1 , 4 . https://doi.org/10.3847/0004-637X/820/1/4
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
Rights
© 2016. The American Astronomical Society. All rights reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at: https://dx.doi.org/10.3847/0004-637X/820/1/4
Description
The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to A.U.. J.S. was partially supported by the Space Exploration Research Fund of The Ohio State University. This research was partly supported by the Polish Ministry of Science and Higher Education (MNiSW) through the program "Iuventus Plus" award No. IP2011 026771. We thank Prof. M. Kubiak for contributing observations to this work as the OGLE Project member. T.S. acknowledges the financial support from the JSPS, JSPS23103002, JSPS24253004, and JSPS26247023. The MOA project is supported by the grants JSPS25103508 and 23340064.Collections
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