UKIRT-2017-BLG-001Lb: A Giant Planet Detected through the Dust
Abstract
We report the discovery of a giant planet in event UKIRT-2017-BLG-001, detected by the United Kingdom Infrared Telescope (UKIRT) microlensing survey. The mass ratio between the planet and its host is q = 1.50^(+0.17)_(-0.14) x 10^(-3), about 1.5 times the Jupiter/Sun mass ratio. The event lies 0.°35 from the Galactic center and suffers from high extinction of A_K = 1.68. Therefore, it could be detected only by a near-infrared (NIR) survey. The field also suffers from large spatial differential extinction, which makes it difficult to estimate the source properties required to derive the angular Einstein radius. Nevertheless, we find evidence suggesting that the source is located in the far disk. If correct, this would be the first source star of a microlensing event to be identified as belonging to the far disk. We estimate the lens mass and distance using a Bayesian analysis to find that the planet's mass is 1.28^(+0.37)_(-0.44) M_J, and it orbits a 0.81^(+0.21)_(-0.27) M⊙ star at an instantaneous projected separation of 4.18^(+0.96)_(-0.88) au. The system is at a distance of 6.3^(+1.6)_(-2.1) kpc, and so likely resides in the Galactic bulge. In addition, we find a non-standard extinction curve in this field, in agreement with previous results toward high-extinction fields near the Galactic center.
Additional Information
© 2018 The American Astronomical Society. Received 2018 February 18; revised 2018 March 11; accepted 2018 March 14; published 2018 April 10. We would like to dedicate this paper to the memory of Neil Gehrels, whose support made the 2017 UKIRT survey possible. We thank M. Irwin for useful discussions, D. Imel for assistance with developing cloud processing for the light curves, and the anonymous referee for important comments that helped to improve the manuscript. Work by Y.S. was supported by an appointment to the NASA Postdoctoral Program at the Jet Propulsion Laboratory, administered by Universities Space Research Association through a contract with NASA. D.M.N. was supported by the Allan C. and Dorothy H. Davis Fellowship. This work was partially supported by NASA grants NNX17AD73G and NNG16PJ32C. UKIRT is owned by the University of Hawaii (UH) and operated by the UH Institute for Astronomy; when some of the data reported here were acquired, UKIRT was supported by NASA and operated under an agreement among the University of Hawaii, the University of Arizona, and Lockheed Martin Advanced Technology Center; operations were enabled through the cooperation of the East Asian Observatory. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 179.B-2002.Attached Files
Published - Shvartzvald_2018_ApJL_857_L8.pdf
Accepted Version - 1802.06795.pdf
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Additional details
- Eprint ID
- 85732
- Resolver ID
- CaltechAUTHORS:20180410-143344827
- NASA Postdoctoral Program
- Allan C. and Dorothy H. Davis Fellowship
- NNX17AD73G
- NASA
- NNG16PJ32C
- NASA
- Created
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2018-04-11Created from EPrint's datestamp field
- Updated
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2021-11-15Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)