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Follow-Up Observations of PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate

Ciardi, David R. and van Eyken, Julian C. and Barnes, Jason W. and Beichman, Charles A. and Carey, Sean J. and Crockett, Christopher J. and Eastman, Jason and Johns-Krull, Christopher M. and Howell, Steve B. and Kane, Stephen R. and McLane, Jacob N. and Plavchan, Peter and Prato, L. and Stauffer, John and van Belle, Gerard T. and von Braun, Kaspar (2015) Follow-Up Observations of PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate. Astrophysical Journal, 809 (1). Art. No. 42. ISSN 0004-637X.

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We present Spitzer 4.5 μm light curve observations, Keck NIRSPEC radial velocity observations, and LCOGT optical light curve observations of PTFO 8-8695, which may host a Jupiter-sized planet in a very short orbital period (0.45 days). Previous work by van Eyken et al. and Barnes et al. predicts that the stellar rotation axis and the planetary orbital plane should precess with a period of 300–600 days. As a consequence, the observed transits should change shape and depth, disappear, and reappear with the precession. Our observations indicate the long-term presence of the transit events (>3 years), and that the transits indeed do change depth, disappear and reappear. The Spitzer observations and the NIRSPEC radial velocity observations (with contemporaneous LCOGT optical light curve data) are consistent with the predicted transit times and depths for the M⋆=0.34 M⊙ precession model and demonstrate the disappearance of the transits. An LCOGT optical light curve shows that the transits do reappear approximately 1 year later. The observed transits occur at the times predicted by a straight-forward propagation of the transit ephemeris. The precession model correctly predicts the depth and time of the Spitzer transit and the lack of a transit at the time of the NIRSPEC radial velocity observations. However, the precession model predicts the return of the transits approximately 1 month later than observed by LCOGT. Overall, the data are suggestive that the planetary interpretation of the observed transit events may indeed be correct, but the precession model and data are currently insufficient to confirm firmly the planetary status of PTFO 8-8695b.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper DOIArticle
Ciardi, David R.0000-0002-5741-3047
van Eyken, Julian C.0000-0003-2192-5371
Beichman, Charles A.0000-0002-5627-5471
Carey, Sean J.0000-0002-0221-6871
Eastman, Jason0000-0003-3773-5142
Howell, Steve B.0000-0002-2532-2853
Kane, Stephen R.0000-0002-7084-0529
Plavchan, Peter0000-0002-8864-1667
Stauffer, John0000-0003-3595-7382
van Belle, Gerard T.0000-0002-8552-158X
von Braun, Kaspar0000-0002-5823-4630
Additional Information:© 2015 The American Astronomical Society. Received 2014 October 8; accepted 2015 June 29; published 2015 August 7. D.R.C. would like to dedicate this paper to his dad Robert A. Ciardi (1940–2013). Robert Ciardi had a passion for learning and knowledge and, in particular, for science. While not able to pursue a career in science for himself, he never stopped thinking and growing, and through his love and encouragement, D.R.C. was able to pursue his own love of exploration and science. In many ways, Robert Ciardi was more excited about this discovery than the authors on this paper. He will be greatly missed. Thank you, Dad. 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 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. This research has made use of the LCOGT Archive, which is operated by the California Institute of Technology, under contract with the Las Cumbres Observatory Global Telescope Network. This work is based, in part, on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Portions of this work were performed at the California Institute of Technology under contract with the National Aeronautics and Space Administration. Facilities: Spitzer (IRAC) - Spitzer Space Telescope satellite, Keck:II (NIRSPEC) - , LCOGT - Las Cumbres Observatory Global Telescope.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:planetary systems – stars: individual (PTFO 8-8695, 2MASS J05250755+0134243, CVSO 30) – stars: pre-main sequence
Issue or Number:1
Record Number:CaltechAUTHORS:20150805-112231886
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:59229
Deposited By: Ruth Sustaita
Deposited On:05 Aug 2015 21:23
Last Modified:27 Nov 2019 18:54

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