Two Stars Two Ways: Confirming a Microlensing Binary Lens Solution with a Spectroscopic Measurement of the Orbit

Creators: Yee, Jennifer C.; Johnson, John Asher; Skowron, Jan; Gould, Andrew; Pineda, J. Sebastian; Eastman, Jason; Vanderburg, Andrew; Howard, Andrew W.

Style

An error occurred while generating the citation.

Abstract

Light curves of microlensing events involving stellar binaries and planetary systems can provide information about the orbital elements of the system due to orbital modulations of the caustic structure. Accurately measuring the orbit in either the stellar or planetary case requires detailed modeling of subtle deviations in the light curve. At the same time, the natural, Cartesian parameterization of a microlensing binary is partially degenerate with the microlens parallax. Hence, it is desirable to perform independent tests of the predictions of microlens orbit models using radial velocity (RV) time series of the lens binary system. To this end, we present 3.5 years of RV monitoring of the binary lens system OGLE-2009-BLG-020 L, for which Skowron et al. constrained all internal parameters of the 200–700 day orbit. Our RV measurements reveal an orbit that is consistent with the predictions of the microlens light curve analysis, thereby providing the first confirmation of orbital elements inferred from microlensing events.

Additional Information

© 2016 The American Astronomical Society. Received 2015 June 3; accepted 2016 March 8; published 2016 April 20. The authors would like to thank Josh Simon, Ian Czekala, Alicia Soderberg, and Atish Kamble for their assistance in obtaining RV data from Magellan. Work by JCY was performed under contract with the California Institute of Technology (Caltech)/Jet Propulsion Laboratory (JPL) funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. AG was supported by NSF grant AST 1103471 and NASA grant NNX12AB99G. JSP was supported by a grant from the National Science Foundation Graduate Research Fellowship under grant no. DGE-1144469. AV is supported by the National Science Foundation Graduate Research Fellowship, Grant No. DGE 1144152. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Facilities: Keck:I (HIRES), Magellan:Clay (MIKE).

Attached Files

Published - apj_821_2_121.pdf

Submitted - 1506.01441v1.pdf

Files

1506.01441v1.pdf

Files (7.4 MB)

Name	Size	Download all
1506.01441v1.pdf md5:be95158c44636cfe06172189f156b03b	468.7 kB	Preview Download
apj_821_2_121.pdf md5:1707eb8db1b8456a66c038b5ab57d13b	7.0 MB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes