TY - JOUR
T1 - Patchy Forsterite Clouds in the Atmospheres of Two Highly Variable Exoplanet Analogs
AU - Vos, Johanna M.
AU - Burningham, Ben
AU - Faherty, Jacqueline K.
AU - Alejandro, Sherelyn
AU - Gonzales, Eileen
AU - Calamari, Emily
AU - Gagliuffi, Daniella Bardalez
AU - Visscher, Channon
AU - Tan, Xianyu
AU - Morley, Caroline V.
AU - Marley, Mark
AU - Gemma, Marina E.
AU - Whiteford, Niall
AU - Gaarn, Josefine
AU - Park, Grace
N1 - © 2023. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/
PY - 2023/2/1
Y1 - 2023/2/1
N2 - We present an atmospheric retrieval analysis of a pair of highly variable, ∼200 Myr old, early T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival 1–15 μm spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg2SiO4) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects, which supports their formation within the same molecular cloud in the Carina-Near moving group. Finally, we note some differences in the constrained abundances of H2O and CO, which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher-quality spectra across a wider wavelength range.
AB - We present an atmospheric retrieval analysis of a pair of highly variable, ∼200 Myr old, early T type planetary-mass exoplanet analogs SIMP J01365662+0933473 and 2MASS J21392676+0220226 using the Brewster retrieval framework. Our analysis, which makes use of archival 1–15 μm spectra, finds almost identical atmospheres for both objects. For both targets, we find that the data is best described by a patchy, high-altitude forsterite (Mg2SiO4) cloud above a deeper, optically thick iron (Fe) cloud. Our model constrains the cloud properties well, including the cloud locations and cloud particle sizes. We find that the patchy forsterite slab cloud inferred from our retrieval may be responsible for the spectral behavior of the observed variability. Our retrieved cloud structure is consistent with the atmospheric structure previously inferred from spectroscopic variability measurements, but clarifies this picture significantly. We find consistent C/O ratios for both objects, which supports their formation within the same molecular cloud in the Carina-Near moving group. Finally, we note some differences in the constrained abundances of H2O and CO, which may be caused by data quality and/or astrophysical processes such as auroral activity and their differing rotation rates. The results presented in this work provide a promising preview of the detail with which we will characterize extrasolar atmospheres with JWST, which will yield higher-quality spectra across a wider wavelength range.
KW - 340
KW - Stars and Stellar Physics
UR - http://www.scopus.com/inward/record.url?scp=85148864142&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/acab58
DO - 10.3847/1538-4357/acab58
M3 - Article
SN - 0004-637X
VL - 944
SP - 1
EP - 20
JO - The Astrophysical Journal
JF - The Astrophysical Journal
IS - 2
M1 - 138
ER -