The Astronomical Journal (Jan 2024)

Orbital and Atmospheric Characterization of the 1RXS J034231.8+121622 System using High-resolution Spectroscopy Confirms that the Companion is a Low-mass Star

  • Clarissa R. Do Ó,
  • Ben Sappey,
  • Quinn M. Konopacky,
  • Jean-Baptiste Ruffio,
  • Kelly K. O’Neil,
  • Tuan Do,
  • Gregory Martinez,
  • Travis S. Barman,
  • Jayke S. Nguyen,
  • Jerry W. Xuan,
  • Christopher A. Theissen,
  • Sarah Blunt,
  • William Thompson,
  • Chih-Chun Hsu,
  • Ashley Baker,
  • Randall Bartos,
  • Geoffrey A. Blake,
  • Benjamin Calvin,
  • Sylvain Cetre,
  • Jacques-Robert Delorme,
  • Greg Doppmann,
  • Daniel Echeverri,
  • Luke Finnerty,
  • Michael P. Fitzgerald,
  • Julie Inglis,
  • Nemanja Jovanovic,
  • Ronald A. López,
  • Dimitri Mawet,
  • Evan Morris,
  • Jacklyn Pezzato,
  • Tobias Schofield,
  • Andrew Skemer,
  • J. Kent Wallace,
  • Jason J. Wang,
  • Ji Wang,
  • Joshua Liberman

DOI
https://doi.org/10.3847/1538-3881/ad3df3
Journal volume & issue
Vol. 167, no. 6
p. 278

Abstract

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The 1RXS J034231.8+121622 system consists of an M dwarf primary and a directly imaged low-mass stellar companion. We use high-resolution spectroscopic data from Keck/KPIC to estimate the objects' atmospheric parameters and radial velocities (RVs). Using PHOENIX stellar models, we find that the primary has a temperature of 3460 ± 50 K and a metallicity of 0.16 ± 0.04, while the secondary has a temperature of 2510 ± 50 K and a metallicity of ${0.13}_{-0.11}^{+0.12}$ . Recent work suggests this system is associated with the Hyades, giving it an older age than previous estimates. Both metallicities agree with current Hyades [Fe/H] measurements (0.11–0.21). Using stellar evolutionary models, we obtain significantly higher masses for the objects, 0.30 ± 0.15 M _⊙ and 0.08 ± 0.01 M _⊙ (84 ± 11 M _Jup ), respectively. Using the RVs and a new astrometry point from Keck/NIRC2, we find that the system is likely an edge-on, moderately eccentric ( ${0.41}_{-0.08}^{+0.27}$ ) configuration. We also estimate the C/O ratio of both objects using custom grid models, obtaining 0.42 ± 0.10 (primary) and 0.55 ± 0.10 (companion). From these results, we confirm that this system most likely went through a binary star formation process in the Hyades. The significant changes in this system's parameters since its discovery highlight the importance of high-resolution spectroscopy for both orbital and atmospheric characterization of directly imaged companions.

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