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WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M_⊕ for OGLE-2012-BLG-0950Lb

Bhattacharya, A. and Beaulieu, J.-P. and Bennett, D. P. and Anderson, J. and Koshimoto, N. and Lu, J. R. and Batista, V. and Blackman, J. W. and Bond, I. A. and Fukui, A. and Henderson, C. B. and Hirao, Y. and Marquette, J. B. and Mróz, P. and Ranc, C. and Udalski, A. (2018) WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M_⊕ for OGLE-2012-BLG-0950Lb. Astronomical Journal, 156 (6). Art. No. 289. ISSN 1538-3881. doi:10.3847/1538-3881/aaed46.

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We present the analysis of the simultaneous high-resolution images from the Hubble Space Telescope and Keck adaptive optics system of the planetary event OGLE-2012-BLG-0950 that determine that the system consists of a 0.58 ± 0.04 M_⊕ host star orbited by a 39 ± 8 M_⊕ planet at a projected separation of 2.54 ± 0.23 au. The planetary system is located at a distance of 2.19 ± 0.23 kpc from Earth. This is the second microlens planet beyond the snow line with a mass measured to be in the mass range 20–80 M_⊕. The runaway gas accretion process of the core accretion model predicts fewer planets in this mass range. This is because giant planets are thought to be growing rapidly at these masses, and they rarely complete growth at this mass. So this result suggests that the core accretion theory may need revision. This analysis also demonstrates the techniques that will be used to measure the masses of planets and their host stars by the WFIRST exoplanet microlensing survey: one-dimensional microlensing parallax combined with the separation and brightness measurement of the unresolved source and host stars to yield multiple redundant constraints on the masses and distance of the planetary system.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Beaulieu, J.-P.0000-0003-0014-3354
Bennett, D. P.0000-0001-8043-8413
Koshimoto, N.0000-0003-2302-9562
Lu, J. R.0000-0001-9611-0009
Batista, V.0000-0002-9782-0333
Blackman, J. W.0000-0001-5860-1157
Fukui, A.0000-0002-4909-5763
Henderson, C. B.0000-0001-8877-9060
Mróz, P.0000-0001-7016-1692
Ranc, C.0000-0003-2388-4534
Udalski, A.0000-0001-5207-5619
Alternate Title:WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M ⊕ for OGLE-2012-BLG-0950Lb
Additional Information:© 2018. The American Astronomical Society. Received 2018 September 7; revised 2018 October 29; accepted 2018 October 30; published 2018 November 30. We acknowledge the help of Dr. Peter Stetson in operating DAOPHOT and providing us with a current version of the code and feedback on our analysis of Keck data. This paper is based in part on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-15455. The Keck Telescope observations and analysis were supported by a NASA Keck PI Data Award, administered by the NASA Exoplanet Science Institute. Data presented herein were obtained at the W. M. Keck Observatory from telescope time allocated to the National Aeronautics and Space Administration through the agency's scientific partnership with the California Institute of Technology and the University of California. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. DPB, AB, and CR were also supported by NASA through grant NASA-80NSSC18K0274. A.U. was supported by the OGLE project funded by National ScienceCentre, Poland with the grant MAESTRO 2014/14/A/ST9/00121.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASANAS 5-26555
W. M. Keck FoundationUNSPECIFIED
National Science Centre (Poland)MAESTRO 2014/14/A/ST9/00121
Subject Keywords:gravitational lensing: micro; planetary systems
Issue or Number:6
Record Number:CaltechAUTHORS:20181130-095502884
Persistent URL:
Official Citation:A. Bhattacharya et al 2018 AJ 156 289
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91360
Deposited By: George Porter
Deposited On:30 Nov 2018 18:32
Last Modified:16 Nov 2021 03:40

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