ARES I: WASP-76 b, A Tale of Two HST Spectra
arXiv:2005.02374 · doi:10.3847/1538-3881/ab9225
Abstract
We analyse the transmission and emission spectra of the ultra-hot Jupiter WASP-76b, observed with the G141 grism of the Hubble Space Telescope's Wide Field Camera 3 (WFC3). We reduce and fit the raw data for each observation using the open-source software Iraclis before performing a fully Bayesian retrieval using the publicly available analysis suite TauRex 3. Previous studies of the WFC3 transmission spectra of WASP-76 b found hints of titanium oxide (TiO) and vanadium oxide (VO) or non-grey clouds. Accounting for a fainter stellar companion to WASP-76, we reanalyse this data and show that removing the effects of this background star changes the slope of the spectrum, resulting in these visible absorbers no longer being detected, eliminating the need for a non-grey cloud model to adequately fit the data but maintaining the strong water feature previously seen. However, our analysis of the emission spectrum suggests the presence of TiO and an atmospheric thermal inversion, along with a significant amount of water. Given the brightness of the host star and the size of the atmospheric features, WASP-76 b is an excellent target for further characterisation with HST, or with future facilities, to better understand the nature of its atmosphere, to confirm the presence of TiO and to search for other optical absorbers.
Accepted for publication in AJ
References in corpus (11)
- Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy
- An ultrahot gas-giant exoplanet with a stratosphere
- ExoMol line lists XVIII. The high temperature spectrum of VO
- Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
- A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
- Detection of titanium oxide in the atmosphere of a hot Jupiter
- Planet formation with envelope enrichment: new insights on planetary diversity
- Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
- Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) - II. A broadened sodium feature on the ultra-hot giant WASP-76b
- An emission spectrum for WASP-121b measured across the 0.8-1.1 micron wavelength range using the Hubble Space Telescope
- Exoplanet Spectroscopy and Photometry with the Twinkle Space Telescope
Cited by in corpus (55)
- ESPRESSO high resolution transmission spectroscopy of WASP-76b
- Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer
- An Atomic Spectral Survey of WASP-76b: Resolving Chemical Gradients and Asymmetries
- Five key exoplanet questions answered via the analysis of 25 hot Jupiter atmospheres in eclipse
- Exploring the Effects of Active Magnetic Drag in a GCM of the Ultra-Hot Jupiter WASP-76b
- A unique hot Jupiter spectral sequence with evidence for compositional diversity
- ARES II: Characterising the Hot Jupiters WASP-127 b, WASP-79 b and WASP-62 b with HST
- Non-local thermodynamic equilibrium effects determine the upper atmospheric temperature structure of the ultra-hot Jupiter KELT-9b
- No umbrella needed: Confronting the hypothesis of iron rain on WASP-76b with post-processed general circulation models
- ARES V: No Evidence For Molecular Absorption in the HST WFC3 Spectrum of GJ 1132 b
- Cloud property trends in hot and ultra-hot giant gas planets (WASP-43b, WASP-103b, WASP-121b, HAT-P-7b, and WASP-18b)
- Spatially-resolving the terminator: Variation of Fe, temperature and winds in WASP-76 b across planetary limbs and orbital phase
- Detection of OH in the ultra-hot Jupiter WASP-76b
- On The Compatibility of Ground-based and Space-based Data: WASP-96 b, An Example
- A comparison of chemical models of exoplanet atmospheres enabled by TauREx 3.1
- ARES III: Unveiling the Two Faces of KELT-7 b with HST WFC3
- High-resolution transmission spectroscopy study of ultra-hot Jupiters HAT-P-57b, KELT-17b, KELT-21b, KELT-7b, MASCARA-1b, and WASP-189b
- Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b
- The Hubble WFC3 Emission Spectrum of the Extremely-Hot Jupiter, KELT-9b
- CRIRES+ detection of CO emissions lines and temperature inversions on the dayside of WASP-18b and WASP-76b
- ARES IV: Probing the atmospheres of the two warm small planets HD 106315 c and HD 3167 c with the HST/WFC3 camera
- Towards multi-dimensional analysis of transmission spectroscopy. Part II: Day-night induced biases in retrievals from hot to ultra-hot Jupiters
- Searching for the origin of the Ehrenreich effect in ultra-hot Jupiters: Evidence for strong C/O gradients in the atmosphere of WASP-76b?
- Retrieval study of cool, directly imaged exoplanet 51 Eri b
- Silicon in the dayside atmospheres of two ultra-hot Jupiters
- KELT-11 b: Abundances of water and constraints on carbon-bearing molecules from the Hubble transmission spectrum
- Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?
- An exploration of model degeneracies with a unified phase curve retrieval analysis: The light and dark sides of WASP-43 b
- The PEPSI Exoplanet Transit Survey (PETS). II. A Deep Search for Thermal Inversion Agents in KELT-20 b/MASCARA-2 b with Emission and Transmission Spectroscopy
- Phase curve pollution of exoplanet transmission spectra
- Toward a multidimensional analysis of transmission spectroscopy. Part I: Computation of transmission spectra using a 1D, 2D, or 3D atmosphere structure
- Confirmation of Water Absorption in the Thermal Emission Spectrum of the Hot Jupiter WASP-77Ab with HST/WFC3
- On spectroscopic phase-curve retrievals: H2 dissociation and thermal inversion in the atmosphere of the ultra-hot Jupiter WASP-103 b
- The transmission spectrum of WASP-17 b from the optical to the near-infrared wavelengths: combining STIS, WFC3 and IRAC datasets
- Measuring Tracers of Planet Formation in the Atmosphere of WASP-77A b: Sub-stellar O/H and C/H ratios, with a stellar C/O ratio and a potentially Super-stellar Ti/H ratio
- Alfnoor: assessing the information content of Ariel's low resolution spectra with planetary population studies
- Characterization of exoplanetary atmospheres with SLOPpy
- Analysis of the planetary mass uncertainties on the accuracy of atmospherical retrieval
- Terminus: A Versatile Simulator for Space-based Telescopes
- Non-Local thermal equilibrium spectra of atmospheric molecules for exoplanets
- Photodissociation and induced chemical asymmetries on ultra-hot gas giants. A case study of HCN on WASP-76 b
- ESPRESSO reveals blueshifted neutral iron emission lines on the dayside of WASP-76 b
- Comparing transit spectroscopy pipelines at the catalogue level: evidence for systematic differences
- Detecting molecules in Ariel low resolution transmission spectra
- ARES VI: Viability of one-dimensional retrieval models for transmission spectroscopy characterization of exo-atmospheres in the era of JWST and Ariel
- ATMOSPHERIX: III- Estimating the C/O ratio and molecular dynamics at the limbs of WASP-76 b with SPIRou
- Converting the sub-Jovian desert of exoplanets to a savanna with TESS, PLATO and Ariel
- The GAPS Programme at TNG. LXIX.The Dayside of WASP-76b revealed by GIANO-B, HARPS-N and ESPRESSO: Evidence for Three-Dimensional Atmospheric Effects
- Spitzer phase curve observations and circulation models of the inflated ultra-hot Jupiter WASP-76b
- RAPOC : the Rosseland and Planck opacity converter. A user-friendly and fast opacity program for Python
- Tracing bulk elemental ratios in exoplanetary atmospheres with TiO chemistry
- Investigation of the upper atmosphere in ultra-hot Jupiter WASP-76 b with high-resolution spectroscopy
- Effect of clouds on emission spectra for Super Venus
- The breaking of cold traps and onset of titanium in ultra-hot Jupiter atmospheres: WASP-189b in context
- Impact of Variable Photospheric Radius on Exoplanet Atmospheric Retrievals