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Published August 2020 | Version Accepted Version + Published
Journal Article Open

OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet orbiting M-dwarf Host in the Inner Galactic Disk

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Abstract

We report the discovery and analysis of the planetary microlensing event OGLE-2017-BLG-0406, which was observed both from the ground and by the Spitzer satellite in a solar orbit. At high magnification, the anomaly in the light curve was densely observed by ground-based-survey and follow-up groups, and it was found to be explained by a planetary lens with a planet/host mass ratio of q = 7.0 × 10⁻⁴ from the light-curve modeling. The ground-only and Spitzer-"only" data each provide very strong one-dimensional (1D) constraints on the 2D microlens parallax vector π_E. When combined, these yield a precise measurement of π_E and of the masses of the host M_(host) = 0.56 ± 0.07 M_⊙ and planet M_(planet) = 0.41 ± 0.05 M_(Jup). The system lies at a distance D_L = 5.2 ± 0.5 kpc from the Sun toward the Galactic bulge, and the host is more likely to be a disk population star according to the kinematics of the lens. The projected separation of the planet from the host is a_⊥ = 3.5 ± 0.3 au (i.e., just over twice the snow line). The Galactic-disk kinematics are established in part from a precise measurement of the source proper motion based on OGLE-IV data. By contrast, the Gaia proper-motion measurement of the source suffers from a catastrophic 10σ error.

Additional Information

© 2020 The American Astronomical Society. Received 2020 April 20; revised 2020 June 4; accepted 2020 June 6; published 2020 July 23. Work by Y.H. was supported by JSPS KAKENHI grant No. 17J02146. D.P.B., A.B., and C.R. were supported by NASA through grant NASA-80NSSC18K0274. Work by N.K. is supported by JSPS KAKENHI grant No. JP18J00897. Work by C.R. was supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by USRA through a contract with NASA. Work by A.G. was supported by AST-1516842 from the US NSF and by JPL grant 1500811. A.G. received support from the European Research Council under the European Unions Seventh Framework Programme (FP 7) ERC grant Agreement No. [321035]. Work by C.H. was supported by the grants of the National Research Foundation of Korea (2017R1A4A1015178 and 2019R1A2C2085965). The MOA project is supported by JSPS KAKENHI grant No. JSPS24253004, JSPS26247023, JSPS23340064, JSPS15H00781, JP16H06287, 17H02871, and 19KK0082. The OGLE project has received funding from the National Science Centre, Poland, grant MAESTRO 2014/14/A/ST9/00121 to AU. This research has made use of the KMTNet system operated by the Korea Astronomy and Space Science Institute (KASI), and the data were obtained at three host sites of CTIO in Chile, SAAO in South Africa, and SSO in Australia. Y.T. acknowledges the support of DFG priority program SPP 1992 "Exploring the Diversity of Extrasolar Planets" (WA 1047/11-1).

Attached Files

Published - Hirao_2020_AJ_160_74.pdf

Accepted Version - 2004.09067.pdf

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2004.09067.pdf

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Additional details

Identifiers

Eprint ID
103858
Resolver ID
CaltechAUTHORS:20200611-133319995

Related works

Describes
https://arxiv.org/abs/2004.09067 (URL)

Funding

Japan Society for the Promotion of Science (JSPS)
17J02146
NASA
80NSSC18K0274
Japan Society for the Promotion of Science (JSPS)
JP18J00897
NASA Postdoctoral Program
NSF
AST-1516842
JPL
1500811
European Research Council (ERC)
321035
National Research Foundation of Korea
2017R1A4A1015178
National Research Foundation of Korea
2019R1A2C2085965
Japan Society for the Promotion of Science (JSPS)
JSPS24253004
Japan Society for the Promotion of Science (JSPS)
JSPS26247023
Japan Society for the Promotion of Science (JSPS)
JSPS23340064
Japan Society for the Promotion of Science (JSPS)
JSPS15H00781
Japan Society for the Promotion of Science (JSPS)
JP16H06287
Japan Society for the Promotion of Science (JSPS)
JP17H02871
Japan Society for the Promotion of Science (JSPS)
JP19KK0082
National Science Centre (Poland)
2014/14/A/ST9/00121
Deutsche Forschungsgemeinschaft (DFG)
WA 1047/11-1

Dates

Created
2020-06-11
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Updated
2022-08-08
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Infrared Processing and Analysis Center (IPAC)