ARES III: Unveiling the Two Faces of KELT-7 b with HST WFC3

Abstract

We present the analysis of the hot-Jupiter KELT-7b using transmission and emission spectroscopy from the Hubble Space Telescope (HST), both taken with the Wide Field Camera 3 (WFC3). Our study uncovers a rich transmission spectrum which is consistent with a cloud-free atmosphere and suggests the presence of H2O and H-. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature-pressure profile, collision induced absorption (CIA) and H-. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additional datasets. Further observations with Hubble, or the next generation of space-based telescopes, are needed to allow for the optical opacity source in transmission to be confirmed and for molecular features to be disentangled in emission.

19 pages, 11 figures, accepted in AJ on June 23, 2020

References in corpus (15)

• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• Tau-REx I: A next generation retrieval code for exoplanetary atmospheres
• An ultrahot gas-giant exoplanet with a stratosphere
• Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• ExoMol line lists XVIII. The high temperature spectrum of VO
• Observing transiting planets with JWST -- Prime targets and their synthetic spectral observations
• New Analysis Indicates No Thermal Inversion in the Atmosphere of HD 209458b
• 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
• ARES I: WASP-76 b, A Tale of Two HST Spectra
• ARES II: Characterising the Hot Jupiters WASP-127 b, WASP-79 b and WASP-62 b with HST
• WASP-52b. The effect of starspot correction on atmospheric retrievals
• A Hubble Space Telescope Search for a Sub-Earth-Sized Exoplanet in the GJ 436 System
• A survey of eight hot Jupiters in secondary eclipse using WIRCam at CFHT

Cited by in corpus (35)

• Five key exoplanet questions answered via the analysis of 25 hot Jupiter atmospheres in eclipse
• A unique hot Jupiter spectral sequence with evidence for compositional diversity
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• Hubble WFC3 Spectroscopy of the Habitable-zone Super-Earth LHS 1140 b
• ARES V: No Evidence For Molecular Absorption in the HST WFC3 Spectrum of GJ 1132 b
• On The Compatibility of Ground-based and Space-based Data: WASP-96 b, An Example
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• A comparison of chemical models of exoplanet atmospheres enabled by TauREx 3.1
• 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
• 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
• 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?
• Retrieval study of cool, directly imaged exoplanet 51 Eri b
• An exploration of model degeneracies with a unified phase curve retrieval analysis: The light and dark sides of WASP-43 b
• Phase curve pollution of exoplanet transmission spectra
• WASP-117 b: an eccentric hot-Saturn as a future complex chemistry laboratory
• Toward a multidimensional analysis of transmission spectroscopy. Part I: Computation of transmission spectra using a 1D, 2D, or 3D atmosphere structure
• 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
• The transmission spectrum of WASP-17 b from the optical to the near-infrared wavelengths: combining STIS, WFC3 and IRAC datasets
• Alfnoor: assessing the information content of Ariel's low resolution spectra with planetary population studies
• Twinkle -- a small satellite spectroscopy mission for the next phase of exoplanet science
• Terminus: A Versatile Simulator for Space-based Telescopes
• Hot exoplanetary atmospheres in 3D
• HORuS transmission spectroscopy and revised planetary parameters of KELT-7b
• Hydride ion continuum hides absorption signatures in the NIRPS near-infrared transmission spectrum of the ultra-hot gas giant WASP-189b
• Comparing transit spectroscopy pipelines at the catalogue level: evidence for systematic differences
• ARES VI: Viability of one-dimensional retrieval models for transmission spectroscopy characterization of exo-atmospheres in the era of JWST and Ariel
• Detecting molecules in Ariel low resolution transmission spectra
• The Hubble PanCET program: The near-ultraviolet transmission spectrum of WASP-79b
• A re-analysis of equilibrium chemistry in five hot Jupiters
• HST/WFC3 Constraints on the Abundances of OH and FeH in the Atmosphere of the Ultra-Hot Neptune LTT-9779 b
• Effect of clouds on emission spectra for Super Venus
• The HUSTLE Program: The UV to Near-IR Transmission Spectrum of the Hot Jupiter KELT-7b