The Astrophysical Journal (Jan 2024)
Validation of Elemental and Isotopic Abundances in Late-M Spectral Types with the Benchmark HIP 55507 AB System
- Jerry W. Xuan,
- Jason Wang,
- Luke Finnerty,
- Katelyn Horstman,
- Simon Grimm,
- Anne E. Peck,
- Eric Nielsen,
- Heather A. Knutson,
- Dimitri Mawet,
- Howard Isaacson,
- Andrew W. Howard,
- Michael C. Liu,
- Sam Walker,
- Mark W. Phillips,
- Geoffrey A. Blake,
- Jean-Baptiste Ruffio,
- Yapeng Zhang,
- Julie Inglis,
- Nicole L. Wallack,
- Aniket Sanghi,
- Erica J. Gonzales,
- Fei Dai,
- Ashley Baker,
- Randall Bartos,
- Charlotte Z. Bond,
- Marta L. Bryan,
- Benjamin Calvin,
- Sylvain Cetre,
- Jacques-Robert Delorme,
- Greg Doppmann,
- Daniel Echeverri,
- Michael P. Fitzgerald,
- Nemanja Jovanovic,
- Joshua Liberman,
- Ronald A. López,
- Emily C. Martin,
- Evan Morris,
- Jacklyn Pezzato,
- Garreth Ruane,
- Ben Sappey,
- Tobias Schofield,
- Andrew Skemer,
- Taylor Venenciano,
- J. Kent Wallace,
- Ji Wang,
- Peter Wizinowich,
- Yinzi Xin,
- Shubh Agrawal,
- Clarissa R. Do Ó,
- Chih-Chun Hsu,
- Caprice L. Phillips
Affiliations
- Jerry W. Xuan
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Jason Wang
- ORCiD
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University , Evanston, IL 60208, USA
- Luke Finnerty
- ORCiD
- Department of Physics & Astronomy, 430 Portola Plaza, University of California , Los Angeles, CA 90095, USA
- Katelyn Horstman
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Simon Grimm
- Center for Space and Habitability, University of Bern , Gesellschaftsstrasse 6, 3012 Bern, Switzerland
- Anne E. Peck
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88003, USA
- Eric Nielsen
- ORCiD
- Department of Astronomy, New Mexico State University , P.O. Box 30001, MSC 4500, Las Cruces, NM 88003, USA
- Heather A. Knutson
- ORCiD
- Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- Dimitri Mawet
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]; Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Howard Isaacson
- ORCiD
- Department of Astronomy, University of California at Berkeley , CA 94720, USA; Centre for Astrophysics, University of Southern Queensland , Toowoomba, QLD, Australia
- Andrew W. Howard
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Michael C. Liu
- ORCiD
- Institute for Astronomy, University of Hawai‘i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA
- Sam Walker
- ORCiD
- Institute for Astronomy, University of Hawai‘i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA
- Mark W. Phillips
- Institute for Astronomy, University of Hawai‘i , 2680 Woodlawn Drive, Honolulu, HI 96822, USA
- Geoffrey A. Blake
- Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- Jean-Baptiste Ruffio
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Yapeng Zhang
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Julie Inglis
- ORCiD
- Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- Nicole L. Wallack
- ORCiD
- Earth and Planets Laboratory, Carnegie Institution for Science , Washington, DC 20015, USA
- Aniket Sanghi
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Erica J. Gonzales
- ORCiD
- Department of Astronomy & Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Fei Dai
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]; Division of Geological & Planetary Sciences, California Institute of Technology , Pasadena, CA 91125, USA
- Ashley Baker
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- 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
- Marta L. Bryan
- ORCiD
- David A. Dunlap Institute Department of Astronomy & Astrophysics, University of Toronto , 50 St. George Street, Toronto, ON M5S 3H4, Canada
- Benjamin Calvin
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]; 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
- 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 ; [email protected]
- 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 ; [email protected]
- Joshua Liberman
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]; James C. Wyant College of Optical Sciences, University of Arizona , Meinel Building, 1630 East University Boulevard, Tucson, AZ 85721, USA
- Ronald A. López
- ORCiD
- 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 ; [email protected]
- Garreth Ruane
- ORCiD
- Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Pasadena, CA 91109, USA
- Ben Sappey
- ORCiD
- 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 ; [email protected]
- Andrew Skemer
- ORCiD
- Department of Astronomy & Astrophysics, University of California , Santa Cruz, CA 95064, USA
- Taylor Venenciano
- Physics and Astronomy Department, Pomona College , 333 North 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
- Ji Wang
- ORCiD
- Department of Astronomy, The Ohio State University , 100 West 18th Avenue, Columbus, OH 43210, USA
- Peter Wizinowich
- W.M. Keck Observatory , 65-1120 Mamalahoa Highway, Kamuela, HI, USA
- Yinzi Xin
- ORCiD
- Department of Astronomy, California Institute of Technology , Pasadena, CA 91125, USA ; [email protected]
- Shubh Agrawal
- ORCiD
- Department of Physics and Astronomy, University of Pennsylvania , Philadelphia, PA 19104, USA
- Clarissa R. Do Ó
- ORCiD
- Center for Astrophysics and Space Sciences, University of California , San Diego, La Jolla, CA 92093, USA
- Chih-Chun Hsu
- ORCiD
- Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University , 1800 Sherman, Evanston, IL 60201, USA
- Caprice L. Phillips
- ORCiD
- Department of Astronomy, The Ohio State University , 100 West 18th Avenue, Columbus, OH 43210, USA
- DOI
- https://doi.org/10.3847/1538-4357/ad1243
- Journal volume & issue
-
Vol. 962,
no. 1
p. 10
Abstract
M dwarfs are common host stars to exoplanets but often lack atmospheric abundance measurements. Late-M dwarfs are also good analogs to the youngest substellar companions, which share similar T _eff ∼ 2300–2800 K. We present atmospheric analyses for the M7.5 companion HIP 55507 B and its K6V primary star with Keck/KPIC high-resolution ( R ∼ 35,000) K -band spectroscopy. First, by including KPIC relative radial velocities between the primary and secondary in the orbit fit, we improve the dynamical mass precision by 60% and find ${M}_{B}={88.0}_{-3.2}^{+3.4}\,{M}_{\mathrm{Jup}}$ , putting HIP 55507 B above the stellar–substellar boundary. We also find that HIP 55507 B orbits its K6V primary star with $a={38}_{-3}^{+4}$ au and e = 0.40 ± 0.04. From atmospheric retrievals of HIP 55507 B, we measure [C/H] = 0.24 ± 0.13, [O/H] = 0.15 ± 0.13, and C/O = 0.67 ± 0.04. Moreover, we strongly detect ^13 CO (7.8 σ significance) and tentatively detect ${{\rm{H}}}_{2}^{18}{\rm{O}}$ (3.7 σ significance) in the companion’s atmosphere and measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={98}_{-22}^{+28}$ and ${{\rm{H}}}_{2}^{16}{\rm{O}}/{{\rm{H}}}_{2}^{18}{\rm{O}}={240}_{-80}^{+145}$ after accounting for systematic errors. From a simplified retrieval analysis of HIP 55507 A, we measure ${}^{12}\mathrm{CO}{/}^{13}\mathrm{CO}={79}_{-16}^{+21}$ and ${{\rm{C}}}^{16}{\rm{O}}/{{\rm{C}}}^{18}{\rm{O}}={288}_{-70}^{+125}$ for the primary star. These results demonstrate that HIP 55507 A and B have consistent ^12 C/ ^13 C and ^16 O/ ^18 O to the <1 σ level, as expected for a chemically homogeneous binary system. Given the similar flux ratios and separations between HIP 55507 AB and systems with young substellar companions, our results open the door to systematically measuring ^13 CO and ${{\rm{H}}}_{2}^{18}{\rm{O}}$ abundances in the atmospheres of substellar or even planetary-mass companions with similar spectral types.
Keywords
