PAPER / ARXIV:2609.20664
Brittany E. Miles , James Mang , Caroline V. Morley , Andrew J. I. Skemer , Melanie Rowland , Brianna Lacy , Genaro Suarez , Channon Visscher , Dániel Apai , Gordon Bjoraker , Aarynn L. Carter , Jacqueline K. Faherty , Jonathan J. Fortney , Nguyen Fuda , Thomas Geballe , Harshil Kothari , Mary Anne Limbach , Mark Marley , Allison M. McCarthy , Adam Schneider , Johanna Vos , Michael Cushing , Richard Freedman , Michael Line , Roxana Lupu , Emily Martin , Mikayla J. Wilson
RESUMO
We present high signal-to-noise, medium resolution (R ~ 1000), time-series JWST/NIRSpec spectra of WISE 0855 (265K), the coldest known brown dwarf. Medium resolution, time-series spectroscopy gives us the power to disentangle the effects of chemistry, temperature, and condensates on this cool world. Our observations span 11 hours with a 15 minute cadence covering 2.87 - 5.27 $\mu$m. The strongest time variable spectroscopic feature is carbon monoxide gas absorption producing modulations with a peak-to-peak amplitude up to 10\% at some wavelengths. Using principal component analysis, we show that the variations in carbon monoxide and phosphine correlate with one another. By comparing our data to atmospheric and structure models we present evidence of patchy water clouds within the atmosphere of WISE 0855. We find that variations in CO and PH$_{3}$ abundances must originate from quenched atmospheric pressures while variations in water cloud thickness occurs at lower pressures.
NO MESMO MAPA