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Friends of Hot Jupiters. II. No Correspondence between Hot-jupiter Spin-Orbit Misalignment and the Incidence of Directly Imaged Stellar Companions

Ngo, Henry and Knutson, Heather A. and Hinkley, Sasha and Crepp, Justin R. and Bechter, Eric B. and Batygin, Konstantin and Howard, Andrew W. and Johnson, John A. and Morton, Timothy D. and Muirhead, Philip S. (2015) Friends of Hot Jupiters. II. No Correspondence between Hot-jupiter Spin-Orbit Misalignment and the Incidence of Directly Imaged Stellar Companions. Astrophysical Journal, 800 (2). Art. No. 138. ISSN 0004-637X.

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Multi-star systems are common, yet little is known about a stellar companion's influence on the formation and evolution of planetary systems. For instance, stellar companions may have facilitated the inward migration of hot Jupiters toward to their present day positions. Many observed short-period gas giant planets also have orbits that are misaligned with respect to their star's spin axis, which has also been attributed to the presence of a massive outer companion on a non-coplanar orbit. We present the results of a multi-band direct imaging survey using Keck NIRC2 to measure the fraction of short-period gas giant planets found in multi-star systems. Over three years, we completed a survey of 50 targets ("Friends of Hot Jupiters") with 27 targets showing some signature of multi-body interaction (misaligned or eccentric orbits) and 23 targets in a control sample (well-aligned and circular orbits). We report the masses, projected separations, and confirmed common proper motion for the 19 stellar companions found around 17 stars. Correcting for survey incompleteness, we report companion fractions of 48% ± 9%, 47% ± 12%, and 51% ± 13% in our total, misaligned/eccentric, and control samples, respectively. This total stellar companion fraction is 2.8σ larger than the fraction of field stars with companions approximately 50-2000 AU. We observe no correlation between misaligned/eccentric hot Jupiter systems and the incidence of stellar companions. Combining this result with our previous radial velocity survey, we determine that 72% ± 16% of hot Jupiters are part of multi-planet and/or multi-star systems.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Ngo, Henry0000-0001-5172-4859
Knutson, Heather A.0000-0002-0822-3095
Hinkley, Sasha0000-0001-8074-2562
Crepp, Justin R.0000-0003-0800-0593
Batygin, Konstantin0000-0002-7094-7908
Howard, Andrew W.0000-0001-8638-0320
Johnson, John A.0000-0001-9808-7172
Morton, Timothy D.0000-0002-8537-5711
Muirhead, Philip S.0000-0002-0638-8822
Additional Information:© 2015 American Astronomical Society. Received 2014 November 3; accepted 2014 December 22; published 2015 February 20. This work was supported by NASA grant NNX14AD24G. H.N. is grateful for funding support from the Natural Sciences and Engineering Research Council of Canada. J.A.J. gratefully acknowledges support from generous fellowships from the David & Lucile Packard and Alfred P. Sloan foundations. We also thank Brendan Bowler for assistance with our common proper motion analysis and Rebekah Dawson and Cristobal Petrovich for helpful discussions. This work was based on observations at the W. M. Keck Observatory granted by the California Institute of Technology. We thank the observers who contributed to the measurements reported here and acknowledge the efforts of the Keck Observatory staff. We extend special thanks to those of Hawaiian ancestry on whose sacred mountain of Mauna Kea we are privileged to be guests.
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Subject Keywords:binaries: close; binaries: eclipsing; methods: observational; planetary systems; planets and satellites: dynamical evolution and stability; techniques: high angular resolution
Issue or Number:2
Record Number:CaltechAUTHORS:20150324-112556645
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Official Citation:Friends of Hot Jupiters. II. No Correspondence between Hot-jupiter Spin-Orbit Misalignment and the Incidence of Directly Imaged Stellar Companions Henry Ngo et al. 2015 ApJ 800 138
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:56022
Deposited By: Ruth Sustaita
Deposited On:24 Mar 2015 19:07
Last Modified:09 Mar 2020 13:18

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