The ESO SupJup Survey. III. Confirmation of ¹³CO in YSES 1 b and Atmospheric Detection of YSES 1 c with CRIRES⁺

December 2024 • 2024AJ....168..246Z

Authors • Zhang, Yapeng • González Picos, Darío • de Regt, Sam • Snellen, Ignas A. G. • Gandhi, Siddharth • Ginski, Christian • Kesseli, Aurora Y. • Landman, Rico • Mollière, Paul • Nasedkin, Evert • Sánchez-López, Alejandro • Stolker, Tomas • Inglis, Julie • Knutson, Heather A. • Mawet, Dimitri • Wallack, Nicole • Xuan, Jerry W.

Abstract • High-resolution spectroscopic characterization of young super-Jovian planets enables precise constraints on elemental and isotopic abundances of their atmospheres. As part of the ESO SupJup Survey, we present high-resolution spectral observations of two wide-orbit super-Jupiters in YSES 1 (or TYC 8998-760-1) using the upgraded VLT/CRIRES⁺ ( ) in K-band. We carry out free atmospheric retrieval analyses to constrain chemical and isotopic abundances, temperature structures, rotation velocities ( ), and radial velocities. We confirm the previous detection of ¹³CO in YSES 1 b at a higher significance of 12.6σ, but point to a higher ¹²CO/¹³CO ratio of 88 ± 13 (1σ confidence interval), consistent with the primary's isotope ratio 66 ± 5. We retrieve a solar-like composition in YSES 1 b with a C/O = 0.57 ± 0.01, indicating a formation via gravitational instability or core accretion beyond the CO iceline. Additionally, the observations lead to detections of H₂O and CO in the outer planet YSES 1 c at 7.3σ and 5.7σ, respectively. We constrain the atmospheric C/O ratio of YSES 1 c to be either solar or subsolar (C/O = 0.36 ± 0.15), indicating the accretion of oxygen-rich solids. The two companions have distinct , 5.34 ± 0.14 km s^‑1 for YSES 1 b and 11.3 ± 2.1 km s^‑1 for YSES 1 c, despite their similar natal environments. This may indicate different spin axis inclinations or effective magnetic braking by the long-lived circumplanetary disk around YSES 1 b. YSES 1 represents an intriguing system for comparative studies of super-Jovian companions and linking present atmospheres to formation histories.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2024AJ....168..246Z
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/ad7ea9/pdf
• PREPRINT http://arxiv.org/abs/2409.16660
• DATA http://archive.eso.org/bin/ads2eso?2024AJ....168..246Z
• ELECTR https://iopscience.iop.org/article/10.3847/1538-3881/ad7ea9