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The 55 Cancri planetary system: fully self-consistent N-body constraints and a dynamical analysis

Nelson, Benjamin E. and Ford, Eric B. and Wright, Jason T. and Fischer, Debra A. and von Braun, Kaspar and Howard, Andrew W. and Payne, Matthew J. and Dindar, Saleh (2014) The 55 Cancri planetary system: fully self-consistent N-body constraints and a dynamical analysis. Monthly Notices of the Royal Astronomical Society, 441 (1). pp. 442-451. ISSN 0035-8711.

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We present an updated study of the planets known to orbit 55 Cancri A using 1 418 high-precision radial velocity observations from four observatories (Lick, Keck, Hobby-Eberly Telescope, Harlan J. Smith Telescope) and transit time/durations for the inner-most planet, 55 Cancri ‘e’ (Winn et al. 2011). We provide the first posterior sample for the masses and orbital parameters based on self-consistent N-body orbital solutions for the 55 Cancri planets, all of which are dynamically stable (for at least 10^8 yr). We apply a GPU version of Radial velocity Using N-body Differential evolution Markov Chain Monte Carlo (RUN DMC; Nelson, Ford & Payne) to perform a Bayesian analysis of the radial velocity and transit observations. Each of the planets in this remarkable system has unique characteristics. Our investigation of high-cadence radial velocities and priors based on space-based photometry yields an updated mass estimate for planet ‘e’ (8.09 ± 0.26 M⊕), which affects its density (5.51±^(1.32)_(1.00)g cm^(−3)) and inferred bulk composition. Dynamical stability dictates that the orbital plane of planet ‘e’ must be aligned to within 60° of the orbital plane of the outer planets (which we assume to be coplanar). The mutual interactions between the planets ‘b’ and ‘c’ may develop an apsidal lock about 180°. We find 36–45 per cent of all our model systems librate about the anti-aligned configuration with an amplitude of 51∘±^(6∘)_(10∘). Other cases showed short-term perturbations in the libration of ϖb − ϖc, circulation, and nodding, but we find the planets are not in a 3:1 mean-motion resonance. A revised orbital period and eccentricity for planet ‘d’ pushes it further towards the closest known Jupiter analogue in the exoplanet population.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Ford, Eric B.0000-0001-6545-639X
Wright, Jason T.0000-0001-6160-5888
Fischer, Debra A.0000-0003-2221-0861
von Braun, Kaspar0000-0002-5823-4630
Howard, Andrew W.0000-0001-8638-0320
Payne, Matthew J.0000-0001-5133-6303
Additional Information:© 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Received: 04 January 2014; Revision Received: 24 February 2014; Accepted: 04 March 2014; Published: 25 April 2014. We would like to thank our referee Sean Raymond for his helpful comments on the manuscript. B.E.N. thanks Eric Feigelson and Brad Hansen for insightful discussions of that helped strengthen the paper. We thank Geoff Marcy and the entire of the California Planet Survey team for their long-term commitment to high-precision RVs for the 55 Cancri system. We also thank Stan Dermott for his contribution to this project. This research was supported by NASA Origins of Solar Systems grant NNX09AB35G and NASA Applied Information Systems Research Programme grant NNX09AM41G. The authors acknowledge the University of Florida High Performance Computing Center for providing computational resources and support that have contributed to the results reported within this paper. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. We extend special thanks to those of Hawai'ian ancestry on whose sacred mountain of Mauna Kea we are privileged to be guests. Without their generous hospitality, the Keck observations presented herein would not have been possible.
Funding AgencyGrant Number
Pennsylvania State UniversityUNSPECIFIED
Eberly College of ScienceUNSPECIFIED
Pennsylvania Space Grant ConsortiumUNSPECIFIED
Subject Keywords:methods: statistical – techniques: radial velocities – planets and satellites: dynamical evolution and stability
Issue or Number:1
Record Number:CaltechAUTHORS:20170619-140658317
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Official Citation:Benjamin E. Nelson, Eric B. Ford, Jason T. Wright, Debra A. Fischer, Kaspar von Braun, Andrew W. Howard, Matthew J. Payne, Saleh Dindar; The 55 Cancri planetary system: fully self-consistent N-body constraints and a dynamical analysis. Mon Not R Astron Soc 2014; 441 (1): 442-451. doi: 10.1093/mnras/stu450
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78336
Deposited By: Tony Diaz
Deposited On:19 Jun 2017 22:33
Last Modified:09 Mar 2020 13:19

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