The Astronomical Journal (Jan 2022)
Retrieving C and O Abundance of HR 8799 c by Combining High- and Low-resolution Data
- Ji Wang,
- Jason J. Wang,
- Jean-Baptiste Ruffio,
- Geoffrey A. Blake,
- Dimitri Mawet,
- Ashley Baker,
- Randall Bartos,
- Charlotte Z. Bond,
- Benjamin Calvin,
- Sylvain Cetre,
- Jacques-Robert Delorme,
- Greg Doppmann,
- Daniel Echeverri,
- Luke Finnerty,
- Michael P. Fitzgerald,
- Nemanja Jovanovic,
- Ronald Lopez,
- Emily C. Martin,
- Evan Morris,
- Jacklyn Pezzato,
- Sam Ragland,
- Garreth Ruane,
- Ben Sappey,
- Tobias Schofield,
- Andrew Skemer,
- Taylor Venenciano,
- J. Kent Wallace,
- Peter Wizinowich,
- Jerry W. Xuan,
- Marta L. Bryan,
- Arpita Roy,
- Nicole L. Wallack
Affiliations
- Ji Wang
- ORCiD
- Department of Astronomy, The Ohio State University , 100 W 18th Avenue, Columbus, OH 43210, USA ; [email protected]
- Jason J. Wang
- ORCiD
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
- Jean-Baptiste Ruffio
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Geoffrey A. Blake
- ORCiD
- Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- Dimitri Mawet
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Ashley Baker
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Randall Bartos
- Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Charlotte Z. Bond
- UK Astronomy Technology Centre, Royal Observatory , Edinburgh EH9 3HJ, UK
- Benjamin Calvin
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Department of Physics & Astronomy, 430 Portola Plaza, University of California , Los Angeles, CA 90095, USA
- Sylvain Cetre
- W. M. Keck Observatory , 65–1120 Mamalahoa Highway, Kamuela, HI, USA
- Jacques-Robert Delorme
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; W. M. Keck Observatory , 65–1120 Mamalahoa Highway, Kamuela, HI, USA
- Greg Doppmann
- W. M. Keck Observatory , 65–1120 Mamalahoa Highway, Kamuela, HI, USA
- Daniel Echeverri
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Luke Finnerty
- ORCiD
- Department of Physics & Astronomy, 430 Portola Plaza, University of California , Los Angeles, CA 90095, USA
- Michael P. Fitzgerald
- ORCiD
- Department of Physics & Astronomy, 430 Portola Plaza, University of California , Los Angeles, CA 90095, USA
- Nemanja Jovanovic
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Ronald Lopez
- Department of Physics & Astronomy, 430 Portola Plaza, University of California , Los Angeles, CA 90095, USA
- Emily C. Martin
- ORCiD
- Department of Astronomy & Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Evan Morris
- Department of Astronomy & Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Jacklyn Pezzato
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Sam Ragland
- W. M. Keck Observatory , 65–1120 Mamalahoa Highway, Kamuela, HI, USA
- Garreth Ruane
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Ben Sappey
- Center for Astrophysics and Space Sciences, University of California , San Diego, La Jolla, CA 92093, USA
- Tobias Schofield
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Andrew Skemer
- ORCiD
- Department of Astronomy & Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Taylor Venenciano
- Physics and Astronomy Department, Pomona College , 333 N. College Way, Claremont, CA 91711, USA
- J. Kent Wallace
- ORCiD
- Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Peter Wizinowich
- ORCiD
- W. M. Keck Observatory , 65–1120 Mamalahoa Highway, Kamuela, HI, USA
- Jerry W. Xuan
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA
- Marta L. Bryan
- ORCiD
- Department of Astronomy, 501 Campbell Hall, University of California at Berkeley , CA 94720, USA
- Arpita Roy
- ORCiD
- Space Telescope Science Institute , 3700 San Martin Drive, Baltimore, MD 21218, USA; Department of Physics and Astronomy, Johns Hopkins University , 3400 N Charles Street, Baltimore, MD 21218, USA
- Nicole L. Wallack
- ORCiD
- Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- DOI
- https://doi.org/10.3847/1538-3881/ac9f19
- Journal volume & issue
-
Vol. 165,
no. 1
p. 4
Abstract
The formation and evolution pathway for the directly imaged multiplanetary system HR 8799 remains mysterious. Accurate constraints on the chemical composition of the planetary atmosphere(s) are key to solving the mystery. We perform a detailed atmospheric retrieval on HR 8799 c to infer the chemical abundances and abundance ratios using a combination of photometric data along with low- and high-resolution spectroscopic data ( R ∼ 20–35,000). We specifically retrieve [C/H], [O/H], and C/O and find them to be ${0.55}_{-0.39}^{+0.36}$ , ${0.47}_{-0.32}^{+0.31}$ , and ${0.67}_{-0.15}^{+0.12}$ at 68% confidence. The superstellar C and O abundances, yet a stellar C/O ratio, reveal a potential formation pathway for HR 8799 c. Planet c, and likely the other gas giant planets in the system, formed early on (likely within ∼1 Myr), followed by further atmospheric enrichment in C and O through the accretion of solids beyond the CO ice line. The enrichment either preceded or took place during the early phase of the inward migration to the current planet locations.
Keywords
