Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD 206893 B

Authors

Kimberly Ward-Duong, Amherst CollegeFollow
J. Patience, School of Earth and Space Exploration
K. Follette, Amherst College
R. J.De Rosa, Stanford University
J. Rameau, Université Grenoble Alpes
M. Marley, NASA Ames Research Center
D. Saumon, Los Alamos National Laboratory
E. L. Nielsen, Stanford University
A. Rajan, Space Telescope Science Institute
A. Z. Greenbaum, University of Michigan, Ann Arbor
J. Lee, University of Georgia
J. J. Wang, California Institute of Technology
I. Czekala, Stanford University
G. Duch ne, Université Grenoble Alpes
B. Macintosh, Stanford University
S. Mark Ammons, Lawrence Livermore National Laboratory
V. P. Bailey, Jet Propulsion Laboratory
T. Barman, The University of Arizona
J. Bulger, University Hawaii Institute for Astronomy
C. Chen, Space Telescope Science Institute
J. Chilcote, Stanford University
T. Cotten, University of Georgia
R. Doyon, University of Montreal
T. M. Esposito, University of California, Berkeley
M. P. Fitzgerald, University of California, Los Angeles
B. L. Gerard, University of California, Santa Cruz
S. J. Goodsell, Gemini Observatory
J. R. Graham, University of California, Berkeley
P. Hibon, European Southern Observatory Santiago
J. Hom, School of Earth and Space Exploration
L. W. Hung, US National Park Service
P. Ingraham, Large Synoptic Survey Telescope

Document Type

Article

Publication Date

1-1-2021

Publication Title

Astronomical Journal

Abstract

We present new near-infrared Gemini Planet Imager (GPI) spectroscopy of HD 206893 B, a substellar companion orbiting within the debris disk of its F5V star. The J, H, K1, and K2 spectra from GPI demonstrate the extraordinarily red colors of the object, confirming it as the reddest substellar object observed to date. The significant flux increase throughout the infrared presents a challenging atmosphere to model with existing grids. Best-fit values vary from 1200 to 1800 K for effective temperature and from 3.0 to 5.0 for log(g), depending on which individual wavelength band is fit and which model suite is applied. The extreme redness of the companion can be partially reconciled by invoking a high-altitude layer of submicron dust particles, similar to dereddening approaches applied to the peculiar red field L dwarf population. However, reconciling the HD 206893 B spectra with even those of the reddest low-gravity L dwarf spectra still requires the contribution of additional atmospheric dust, potentially due to the debris disk environment in which the companion resides. Orbit fitting from 4 yr of astrometric monitoring is consistent with a ∼30 yr period, an orbital inclination of 147 , and a semimajor axis of 10 au, well within the estimated disk inner radius of ∼50 au. As one of a very few substellar companions imaged interior to a circumstellar disk, the properties of this system offer important dynamical constraints on companion-disk interaction and provide a benchmark for substellar and planetary atmospheric study.

Volume

161

Issue

1

DOI

10.3847/1538-3881/abc263

ISSN

00046256

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Rights

© 2021. The Author(s)

Comments

Archived as published.

Recommended Citation

Ward-Duong, Kimberly; Patience, J.; Follette, K.; Rosa, R. J.De; Rameau, J.; Marley, M.; Saumon, D.; Nielsen, E. L.; Rajan, A.; Greenbaum, A. Z.; Lee, J.; Wang, J. J.; Czekala, I.; Duch ne, G.; Macintosh, B.; Ammons, S. Mark; Bailey, V. P.; Barman, T.; Bulger, J.; Chen, C.; Chilcote, J.; Cotten, T.; Doyon, R.; Esposito, T. M.; Fitzgerald, M. P.; Gerard, B. L.; Goodsell, S. J.; Graham, J. R.; Hibon, P.; Hom, J.; Hung, L. W.; and Ingraham, P., "Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD 206893 B" (2021). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/103