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Direct Detection and Orbital Analysis of the Exoplanets HR 8799 bcd from Archival 2005 Keck/NIRC2 Data

Currie, Thayne and Fukagawa, Misato and Thalmann, Christian and Matsumura, Soko and Plavchan, Peter (2012) Direct Detection and Orbital Analysis of the Exoplanets HR 8799 bcd from Archival 2005 Keck/NIRC2 Data. Astrophysical Journal Letters, 755 (2). Art. No. L34. ISSN 2041-8205. doi:10.1088/2041-8205/755/2/L34.

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We present previously unpublished 2005 July H-band coronagraphic data of the young, planet-hosting star HR 8799 from the newly released Keck/NIRC2 archive. Despite poor observing conditions, we detect three of the planets (HR 8799 bcd), two of them (HR 8799 bc) without advanced image processing. Comparing these data with previously published 1998-2011 astrometry and that from re-reduced 2010 October Keck data constrains the orbits of the planets. Analyzing the planets' astrometry separately, HR 8799 d's orbit is likely inclined at least 25° from face-on and the others may be on inclined orbits. For semimajor axis ratios consistent with a 4:2:1 mean-motion resonance, our analysis yields precise values for HR 8799 bcd's orbital parameters and strictly constrains the planets' eccentricities to be less than 0.18-0.3. However, we find no acceptable orbital solutions with this resonance that place the planets in face-on orbits; HR 8799 d shows the largest deviation from such orbits. Moreover, few orbits make HR 8799 d coplanar with b and c, whereas dynamical stability analyses used to constrain the planets' masses typically assume coplanar and/or face-on orbits. This Letter illustrates the significant science gain enabled with the release of the NIRC2 archive.

Item Type:Article
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URLURL TypeDescription
Currie, Thayne0000-0002-7405-3119
Plavchan, Peter0000-0002-8864-1667
Additional Information:© 2012 American Astronomical Society. Received 2012 May 30; accepted 2012 July 5; published 2012 August 7. We thank Christian Marois, Scott Kenyon, and the anonymous referee for helpful comments. This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration. We are extremely grateful to the NExScI/KOA staff for developing and maintaining the NIRC2 archive. T.C. is supported by a NASA Postdoctoral Fellowship; S.M. is supported by an Astronomy Center for Theory and Computation Prize Fellowship at the University of Maryland.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
NASA Postdoctoral FellowshipUNSPECIFIED
University of MarylandUNSPECIFIED
Subject Keywords:planetary systems; stars: early-type; stars: individual (HR 8799)
Issue or Number:2
Record Number:CaltechAUTHORS:20120925-114224031
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Official Citation:Direct Detection and Orbital Analysis of the Exoplanets HR 8799 bcd from Archival 2005 Keck/NIRC2 Data Thayne Currie et al. 2012 ApJ 755 L34
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:34353
Deposited By: Ruth Sustaita
Deposited On:25 Sep 2012 19:08
Last Modified:09 Nov 2021 23:08

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