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A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau

Johns-Krull, Christopher M. and McLane, Jacob N. and Prato, L. and Crockett, Christopher J. and Jaffe, Daniel T. and Hartigan, Patrick M. and Beichman, Charles A. and Mahmud, Naved I. and Chen, Wei and Skiff, B. A. and Cauley, P. Wilson and Jones, Joshua A. and Mace, G. N. (2016) A Candidate Young Massive Planet in Orbit around the Classical T Tauri Star CI Tau. Astrophysical Journal, 826 (2). Art. No. 206. ISSN 0004-637X. doi:10.3847/0004-637X/826/2/206.

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The ~2 Myr old classical T Tauri star CI Tau shows periodic variability in its radial velocity (RV) variations measured at infrared (IR) and optical wavelengths. We find that these observations are consistent with a massive planet in a ~9 day period orbit. These results are based on 71 IR RV measurements of this system obtained over five years, and on 26 optical RV measurements obtained over nine years. CI Tau was also observed photometrically in the optical on 34 nights over ~one month in 2012. The optical RV data alone are inadequate to identify an orbital period, likely the result of star spot and activity-induced noise for this relatively small data set. The infrared RV measurements reveal significant periodicity at ~9 days. In addition, the full set of optical and IR RV measurements taken together phase coherently and with equal amplitudes to the ~9 day period. Periodic RV signals can in principle be produced by cool spots, hotspots, and reflection of the stellar spectrum off the inner disk, in addition to resulting from a planetary companion. We have considered each of these and find the planet hypothesis most consistent with the data. The RV amplitude yields an M sin i of ~8.1 M_(Jup); in conjunction with a 1.3 mm continuum emission measurement of the circumstellar disk inclination from the literature, we find a planet mass of ~11.3 M_(Jup), assuming alignment of the planetary orbit with the disk.

Item Type:Article
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URLURL TypeDescription Paper
Jaffe, Daniel T.0000-0003-3577-3540
Beichman, Charles A.0000-0002-5627-5471
Mace, G. N.0000-0001-7875-6391
Additional Information:© 2016 American Astronomical Society. Received 2015 October 1; revised 2016 May 7; accepted 2016 May 16; published 2016 August 1. We thank the IRTF TOs Dave Griep, Bill Golisch, and Eric Volquardsen and SAs John Rayner, Mike Connelly, and Bobby Bus, the Keck Observatory OAs Cynthia Wilburn and Heather Hershley and SAs Scott Dahm and Greg Wirth, KPNO staff Dave Summers, Di Harmer, and Dick Joyce, and Dave Doss of McDonald Observatory for their exceptional observing support over the many years of this program. L.P. is grateful to Peter Bodenheimer, Joe Llama, Evgenya Shkolnik, and Ben Zuckerman for insightful discussions. Partial support for this research was provided by the SIM Young Planets Key Project and by NASA Origins grants 05-SSO05-86 and 07-SSO07-86 to L.P. Additional support for this work was provided by the NSF through grant AST-1212122 made to Rice University. We are grateful to the Arizona Space Grant consortium for support of J.N.M.'s participation in this work. We wish to thank an anonymous referee for many helpful comments that improved the manuscript. This work made use of the SIMBAD reference database, the NASA Astrophysics Data System, and the data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This work made use of the Immersion Grating Infrared Spectrograph (IGRINS) that was developed under a collaboration between the University of Texas at Austin and the Korea Astronomy and Space Science Institute (KASI) with the financial support of the U.S. National Science Foundation under grant AST-1229522, of the University of Texas at Austin, and of the Korean GMT Project of KASI. Some 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 recognize and acknowledge the significant cultural role that the summit of Mauna Kea plays within the indigenous Hawaiian community. We are grateful for the opportunity to conduct observations from this special mountain.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
SIM Young Planets Key ProjectUNSPECIFIED
W. M. Keck FoundationUNSPECIFIED
Arizona Space Grant ConsortiumUNSPECIFIED
Subject Keywords:planets and satellites: formation; stars: individual (CI Tau) ; stars: low-mass; stars: pre-main sequence; star spots ; techniques: radial velocities
Issue or Number:2
Record Number:CaltechAUTHORS:20161003-095120989
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Official Citation:Christopher M. Johns-Krull et al 2016 ApJ 826 206
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:70753
Deposited By: Ruth Sustaita
Deposited On:03 Oct 2016 18:29
Last Modified:11 Nov 2021 04:34

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