Global climate and atmospheric composition of the ultra-hot jupiter wasp-103b from hst and spitzer phase curve observations

Laura Kreidberg, Michael R. Line, Vivien Parmentier, Kevin B. Stevenson, Tom Louden, Mickäel Bonnefoy, Jacqueline K. Faherty, Gregory W. Henry, Michael H. Williamson, Keivan Stassun, Thomas G. Beatty, Jacob L. Bean, Jonathan J. Fortney, Adam P. Showman, Jean Michel Désert, Jacob Arcangeli

Research output: Contribution to journalArticlepeer-review

Abstract

We present thermal phase curve measurements for the hot Jupiter WASP-103b observed with Hubble/WFC3 and Spitzer/IRAC. The phase curves have large amplitudes and negligible hotspot offsets, indicative of poor heat redistribution to the nightside. We fit the phase variation with a range of climate maps and find that a spherical harmonics model generally provides the best fit. The phase-resolved spectra are consistent with blackbodies in the WFC3 bandpass, with brightness temperatures ranging from 1880 ± 40 K on the nightside to 2930 ± 40 K on the dayside. The dayside spectrum has a significantly higher brightness temperature in the Spitzer bands, likely due to CO emission and a thermal inversion. The inversion is not present on the nightside. We retrieved the atmospheric composition and found the composition is moderately metal-enriched ([M/H] = 23+2913× solar) and the carbon-to-oxygen ratio is below 0.9 at 3 σ confidence. In contrast to cooler hot Jupiters, we do not detect spectral features from water, which we attribute to partial H2O dissociation. We compare the phase curves to 3D general circulation models and find magnetic drag effects are needed to match the data. We also compare the WASP-103b spectra to brown dwarfs and young directly imaged companions and find these objects have significantly larger water features, indicating that surface gravity and irradiation environment play an important role in shaping the spectra of hot Jupiters. These results highlight the 3D structure of exoplanet atmospheres and illustrate the importance of phase curve observations for understanding their complex chemistry and physics.

Original languageEnglish (US)
JournalUnknown Journal
StatePublished - Apr 30 2018

Keywords

  • Planets
  • Planets and satellites: individual (WASP-103b)
  • Satellites: atmospheres

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Global climate and atmospheric composition of the ultra-hot jupiter wasp-103b from hst and spitzer phase curve observations'. Together they form a unique fingerprint.

Cite this