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MOA 2010-BLG-477Lb: Constraining the Mass of a microlensing planet from microlensing parallax, orbital motion, and detection of blended light


Bachelet, E and Shin, I-G and Han, C and Fouque, P and Gould, A and Menzies, JW and Beaulieu, J-P and Bennett, DP and Bond, IA and Dong, S and Heyrovsky, D and Marquette, J-B and Marshall, J and Skowron, J and Street, RA and Sumi, T and Udalski, A and Abe, L and Agabi, K and Albrow, MD and Allen, W and Bertin, E and Bos, M and Bramich, DM and Chavez, J and Christie, GW and Cole, AA and Crouzet, N and Dieters, S and Dominik, M and Drummond, J and Greenhill, JG and Guillot, T and Henderson, CB and Hessman, FV and Horne, K and Hundertmark, M and Johnson, JA and Jorgensen, UG and Kandori, R and Liebig, C and Mekarnia, D and McCormick, J and Moorhouse, D and Nagayama, T and Nataf, D and Natusch, T and Nishiyama, S and Rivet, J-P and Sahu, KC and Shvartzvald, Y and Thornley, G and Tomczak, AR and Tsapras, Y and Yee, JC and The PLANET Collaboration, The FUN muCollaboration, The MOA Collaboration, The OGLE Collaboration, The RoboNet Collaboration and The MiNDSTEp Collaboration, MOA 2010-BLG-477Lb: Constraining the Mass of a microlensing planet from microlensing parallax, orbital motion, and detection of blended light, The Astrophysical Journal, 754, (1) Article 73. ISSN 0004-637X (2012) [Refereed Article]

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Copyright 2012 The American Astronomical Society

DOI: doi:10.1088/0004-637X/754/1/73


Microlensing detections of cool planets are important for the construction of an unbiased sample to estimate the frequency of planets beyond the snow line, which is where giant planets are thought to form according to the core accretion theory of planet formation. In this paper, we report the discovery of a giant planet detected from the analysis of the light curve of a high-magnification microlensing event MOA 2010-BLG-477. The measured planet-star mass ratio is q = (2.181 ± 0.004) × 10–3 and the projected separation is s = 1.1228 ± 0.0006 in units of the Einstein radius. The angular Einstein radius is unusually large θE = 1.38 ± 0.11 mas. Combining this measurement with constraints on the "microlens parallax" and the lens flux, we can only limit the host mass to the range 0.13 < M/M < 1.0. In this particular case, the strong degeneracy between microlensing parallax and planet orbital motion prevents us from measuring more accurate host and planet masses. However, we find that adding Bayesian priors from two effects (Galactic model and Keplerian orbit) each independently favors the upper end of this mass range, yielding star and planet masses of M* = 0.67+0.33–0.13 M and mp = 1.5+0.8–0.3 MJUP at a distance of D = 2.3 ± 0.6 kpc, and with a semi-major axis of a = 2+3–1 AU. Finally, we show that the lens mass can be determined from future high-resolution near-IR adaptive optics observations independently from two effects, photometric and astrometric.

Item Details

Item Type:Refereed Article
Keywords:gravitational lensing: micro; planetary systems
Research Division:Physical Sciences
Research Group:Astronomical sciences
Research Field:Stellar astronomy and planetary systems
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the physical sciences
UTAS Author:Cole, AA (Associate Professor Andrew Cole)
UTAS Author:Dieters, S (Dr Stefan Dieters)
UTAS Author:Greenhill, JG (Dr John Greenhill)
ID Code:78789
Year Published:2012
Web of Science® Times Cited:30
Deposited By:Mathematics and Physics
Deposited On:2012-07-26
Last Modified:2017-11-06

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