High-contrast Imaging around a 2 Myr-old CI Tau with a Close-in Gas Giant
Abstract
Giant planets around young stars serve as a clue to unveiling their formation history and orbital evolution. CI Tau is a 2 Myr-old classical T Tauri star hosting an eccentric hot Jupiter, CI Tau b. The standard formation scenario of a hot Jupiter predicts that planets formed further out and migrated inward. A high eccentricity of CI Tau b may be suggestive of high-e migration due to secular gravitational perturbations by an outer companion. Also, the Atacama Large Millimeter/submillimeter Array 1.3 mm-continuum observations show that CI Tau has at least three annular gaps in which unseen planets may exist. We present high-contrast imaging around CI Tau taken from the Keck/NIRC2 _(L')-band filter and vortex coronagraph that allows us to search for an outer companion. We did not detect any outer companion around CI Tau from angular differential imaging (ADI) using two deep imaging data sets. The detection limits from ADI-reduced images rule out the existence of an outer companion beyond ∼30 au that can cause the Kozai–Lidov migration of CI Tau b. Our results suggest that CI Tau b may have experienced type II migration from ≲2 au in megayears. We also confirm that no planets with ≥ 2–4 M_Jup are hidden in two outer gaps.
Additional Information
We are grateful to Dimitri Mawet and Garreth Ruane for sharing the NIRC2 data taken in their observational programs. T.U. is supported by Grant-in-Aid for Japan Society for the Promotion of Science (JSPS) Fellows and JSPS KAKENHI grant No. JP21J01220. Y.H. was partly supported by JSPS KAKENHI grant No. 18H05439. M.T. is supported by JSPS KAKENHI grant Nos. 18H05442, 15H02063, and 22000005. This research is partially supported by NASA ROSES XRP, award 80NSSC19K0294. 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 Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain.Additional details
- Eprint ID
- 118811
- Resolver ID
- CaltechAUTHORS:20230117-369491100.15
- JP21J01220
- Japan Society for the Promotion of Science (JSPS)
- 18H05439
- Japan Society for the Promotion of Science (JSPS)
- 18H05442
- Japan Society for the Promotion of Science (JSPS)
- 15H02063
- Japan Society for the Promotion of Science (JSPS)
- 22000005
- Japan Society for the Promotion of Science (JSPS)
- 80NSSC19K0294
- NASA
- W. M. Keck Foundation
- Created
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2023-02-10Created from EPrint's datestamp field
- Updated
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2023-02-10Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)