WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M_⊕ for OGLE-2012-BLG-0950Lb
Abstract
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.
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.Attached Files
Published - Bhattacharya_2018_AJ_156_289.pdf
Submitted - 1809.02654
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Additional details
- Alternative title
- WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M ⊕ for OGLE-2012-BLG-0950Lb
- Eprint ID
- 91360
- Resolver ID
- CaltechAUTHORS:20181130-095502884
- NAS 5-26555
- NASA
- GO-15455
- NASA
- W. M. Keck Foundation
- 80NSSC18K0274
- NASA
- MAESTRO 2014/14/A/ST9/00121
- National Science Centre (Poland)
- Created
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2018-11-30Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)