Dynamical Constraints On the HR 8799 Planets With GPI

Authors

• Jason J. Wang, University of California, Berkeley
• James R. Graham, University of California, Berkeley
• Rebekah Dawson, Pennsylvania State University
• Daniel Fabrycky, The University of Chicago
• Robert J. De Rosa, University of California, Berkeley
• Laurent Pueyo, Space Telescope Science Institute
• Quinn Konopacky, Center for Astrophysics & Space Sciences
• Bruce Macintosh, Kavli Institute for Particle Astrophysics and Cosmology
• Christian Marois, National Research Council Canada
• Eugene Chiang, University of California, Berkeley
• S. Mark Ammons, Lawrence Livermore National Laboratory
• Pauline Arriaga, University of California, Los Angeles
• Vanessa P. Bailey, Jet Propulsion Laboratory
• Travis Barman, The University of Arizona
• Joanna Bulger, National Institutes of Natural Sciences - National Astronomical Observatory of Japan
• Jeffrey Chilcote, University of Notre Dame
• Tara Cotten, University of Georgia
• Rene Doyon, Institut de Recherche sur les Exoplanètes
• Gaspard Duchêne, University of California, Berkeley
• Thomas M. Esposito, University of California, Berkeley
• Michael P. Fitzgerald, University of California, Los Angeles
• Katherine B. Follette, Amherst College
• Benjamin L. Gerard, National Research Council Canada
• Stephen J. Goodsell, Gemini Observatory
• Alexandra Z. Greenbaum, University of Michigan, Ann Arbor
• Pascale Hibon, European Southern Observatory Santiago
• Li Wei Hung, US National Park Service
• Patrick Ingraham, Large Synoptic Survey Telescope
• Paul Kalas, University of California, Berkeley
• James E. Larkin, University of California, Los Angeles
• Jérôme Maire, Center for Astrophysics & Space Sciences
• Franck Marchis, SETI Institute
• Kimberly Ward-Duong, Arizona State UniversityFollow

Document Type

Article

Publication Date

11-1-2018

Publication Title

Astronomical Journal

Abstract

The HR 8799 system uniquely harbors four young super-Jupiters whose orbits can provide insights into the system's dynamical history and constrain the masses of the planets themselves. Using the Gemini Planet Imager, we obtained down to one milliarcsecond precision on the astrometry of these planets. We assessed four-planet orbit models with different levels of constraints and found that assuming the planets are near 1:2:4:8 period commensurabilities, or are coplanar, does not worsen the fit. We added the prior that the planets must have been stable for the age of the system (40 Myr) by running orbit configurations from our posteriors through N-body simulations and varying the masses of the planets. We found that only assuming the planets are both coplanar and near 1:2:4:8 period commensurabilities produces dynamically stable orbits in large quantities. Our posterior of stable coplanar orbits tightly constrains the planets' orbits, and we discuss implications for the outermost planet b shaping the debris disk. A four-planet resonance lock is not necessary for stability up to now. However, planet pairs d and e, and c and d, are each likely locked in two-body resonances for stability if their component masses are above 6 M Jup and 7 M Jup, respectively. Combining the dynamical and luminosity constraints on the masses using hot-start evolutionary models and a system age of 42 ± 5 Myr, we found the mass of planet b to be 5.8 ± 0.5 M Jup, and the masses of planets c, d, and e to be each.

Keywords

astrometry, planetdisk interactions, planets and satellites: dynamical evolution and stability, planets and satellites: gaseous planets, stars: individual (HR 8799), techniques: high angular resolution

Volume

156

Issue

5

DOI

https://doi.org/10.3847/1538-3881/aae150

ISSN

00046256

Rights

© 2018. The American Astronomical Society

Version

Version of Record

Recommended Citation

Wang, Jason J.; Graham, James R.; Dawson, Rebekah; Fabrycky, Daniel; De Rosa, Robert J.; Pueyo, Laurent; Konopacky, Quinn; Macintosh, Bruce; Marois, Christian; Chiang, Eugene; Ammons, S. Mark; Arriaga, Pauline; Bailey, Vanessa P.; Barman, Travis; Bulger, Joanna; Chilcote, Jeffrey; Cotten, Tara; Doyon, Rene; Duchêne, Gaspard; Esposito, Thomas M.; Fitzgerald, Michael P.; Follette, Katherine B.; Gerard, Benjamin L.; Goodsell, Stephen J.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hung, Li Wei; Ingraham, Patrick; Kalas, Paul; Larkin, James E.; Maire, Jérôme; Marchis, Franck; and Ward-Duong, Kimberly, "Dynamical Constraints On the HR 8799 Planets With GPI" (2018). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/121