Transmission spectroscopy with VLT FORS2: a featureless spectrum for the low-density transiting exoplanet WASP-88b

Abstract

We present ground-based optical transmission spectroscopy of the low-density hot Jupiter WASP-88b covering the wavelength range 4413-8333 Å with the FORS2 spectrograph on the Very Large Telescope. The FORS2 white light curves exhibit a significant time-correlated noise which we model using a Gaussian Process and remove as a wavelength-independent component from the spectroscopic light curves. We analyse complementary photometric observations from the Transiting Exoplanet Survey Satellite and refine the system properties and ephemeris. We find a featureless transmission spectrum with increased absorption towards shorter wavelengths. We perform an atmospheric retrieval analysis with the AURA code, finding tentative evidence for haze in the upper atmospheric layers and a lower likelihood for a dense cloud deck. Whilst our retrieval analysis results point toward clouds and hazes, further evidence is needed to definitively reject a clear-sky scenario.

arXiv comment19 pages, 12 figures, 3 tables, Accepted for publication in MNRAS

References in corpus (91)

• emcee: The MCMC Hammer
• The Transiting Exoplanet Survey Satellite
• Analytic Lightcurves for Planetary Transit Searches
• The James Webb Space Telescope
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Detection of an Extrasolar Planet Atmosphere
• batman: BAsic Transit Model cAlculatioN in Python
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• A Unified Theory for the Atmospheres of the Hot and Very Hot Jupiters: Two Classes of Irradiated Atmospheres
• Theoretical Transmission Spectra During Extrasolar Giant Planet Transits
• A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres
• Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
• A Possible Bifurcation in Atmospheres of Strongly Irradiated Stars and Planets
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• Rayleigh scattering in the transit spectrum of HD 189733b
• A ground-based transmission spectrum of the super-Earth exoplanet GJ1214b
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Albedo and Reflection Spectra of Extrasolar Giant Planets
• Water Vapor in the Spectrum of the Extrasolar Planet HD 189733b: 1. the Transit
• Limb and gravity-darkening coefficients for the TESS satellite at several metallicities, surface gravities, and microturbulent velocities
• Transitions in the cloud composition of hot Jupiters
• Transmission Spectra of Three-Dimensional Hot Jupiter Model Atmospheres
• The Effect of Condensates on the Characterization of Transiting Planet Atmospheres with Transmission Spectroscopy
• A Gaussian process framework for modelling instrumental systematics: application to transmission spectroscopy
• Homogeneous studies of transiting extrasolar planets. III. Additional planets and stellar models
• Fingering convection and cloudless models for cool brown dwarf atmospheres
• Aerosol Composition of Hot Giant Exoplanets Dominated by Silicates and Hydrocarbon Hazes
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering
• Mass-Metallicity Trends in Transiting Exoplanets from Atmospheric Abundances of H${}_2$O, Na, and K
• H${}_2$O abundances and cloud properties in ten hot giant exoplanets
• The Optical and Near-Infrared Transmission Spectrum of the Super-Earth GJ1214b: Further Evidence for a Metal-Rich Atmosphere
• HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
• Cloudless atmospheres for L/T dwarfs and extra-solar giant planets
• HST/STIS Optical Transit Transmission Spectra of the hot-Jupiter HD209458b
• An HST Optical to Near-IR Transmission Spectrum of the Hot Jupiter WASP-19b: Detection of Atmospheric Water and Likely Absence of TiO
• Accuracy tests of radiation schemes used in hot Jupiter global circulation models
• ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar Photosphere
• ACCESS: A featureless optical transmission spectrum for WASP-19b from Magellan/IMACS
• Homogeneous studies of transiting extrasolar planets. V. New results for 38 planets
• An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet
• Retrieval of planetary and stellar properties in transmission spectroscopy with Aura
• The Stagger-grid: A grid of 3D stellar atmosphere models - IV. Limb darkening coefficients
• Quantifying and Predicting the Presence of Clouds in Exoplanet Atmospheres
• A Gemini ground-based transmission spectrum of WASP-29b: a featureless spectrum from 515 to 720nm
• Hubble Space Telescope hot Jupiter Transmission Spectral Survey: detection of water in HAT-P-1b from Wide Field Camera 3 near-infrared spatial scan observations
• Python Leap Second Management and Implementation of Precise Barycentric Correction (barycorrpy)
• The solar-type eclipsing binary system LL Aquarii
• A library of ATMO forward model transmission spectra for hot Jupiter exoplanets
• Forward modelling and retrievals with PLATON, a fast open source tool
• VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground
• GTC OSIRIS transiting exoplanet atmospheric survey: detection of sodium in XO-2b from differential long-slit spectroscopy
• The optical transmission spectrum of the hot Jupiter HAT-P-32b: clouds explain the absence of broad spectral features?
• PLATON II: New Capabilities And A Comprehensive Retrieval on HD 189733b Transit and Eclipse Data
• On degeneracies in retrievals of exoplanetary transmission spectra
• Physical properties, transmission and emission spectra of the WASP-19 planetary system from multi-colour photometry
• On Signatures of Clouds in Exoplanetary Transit Spectra
• A Cloudiness Index for Transiting Exoplanets Based on the Sodium and Potassium Lines: Tentative Evidence for Hotter Atmospheres Being Less Cloudy at Visible Wavelengths
• Transits and Occultations
• Rayleigh scattering in the transmission spectrum of HAT-P-18b
• Reliable inference of exoplanet light curve parameters using deterministic and stochastic systematics models
• Transmission spectroscopy of the sodium 'D' doublet in WASP-17b with the VLT
• VLT/FORS2 comparative transmission spectroscopy II: confirmation of a cloud-deck and Rayleigh scattering in WASP-31b, but no potassium?
• Super-Rayleigh Slopes in Transmission Spectra of Exoplanets Generated by Photochemical Haze
• FORS2 observes a multi-epoch transmission spectrum of the hot Saturn-mass exoplanet WASP-49b
• A Library of Self-Consistent Simulated Exoplanet Atmospheres
• An optical transmission spectrum of the ultra-hot Jupiter WASP-33b. First indication of AlO in an exoplanet
• The TESS light curve of AI Phoenicis
• Signs of strong Na and K absorption in the transmission spectrum of WASP-103b
• Potassium detection in the clear atmosphere of a hot-Jupiter: FORS2 transmission spectroscopy of WASP-17b
• HST PanCET program: A Cloudy Atmosphere for the promising JWST target WASP-101b
• Transmission spectroscopy of HAT-P-32b with the LBT: confirmation of clouds/hazes in the planetary atmosphere
• Into the UV: A precise transmission spectrum of HAT-P-41b using Hubble's WFC3/UVIS G280 grism
• Detection of Na, K and H${}_2$O in the hazy atmosphere of WASP-6b
• Detection of sodium absorption in WASP-17b with Magellan
• Fully scalable forward model grid of exoplanet transmission spectra
• SWEET-Cat update and FASMA. A new minimization procedure for stellar parameters using high-quality spectra
• A multiplicity study of transiting exoplanet host stars. I. High-contrast imaging with VLT/SPHERE
• Revisiting the potassium feature of WASP-31b at high-resolution
• Contamination from a nearby star cannot explain the anomalous transmission spectrum of the ultra-short period giant planet WASP-103b
• The HST PanCET Program: An Optical to Infrared Transmission Spectrum of HAT-P-32Ab
• Regaining the FORS: optical ground-based transmission spectroscopy of the exoplanet WASP-19b with VLT+FORS2
• Ground-Based Transmission Spectroscopy with FORS2: A featureless optical transmission spectrum and detection of H${}_2$O for the ultra-hot Jupiter WASP-103b
• ACCESS: A Visual to Near-infrared Spectrum of the Hot Jupiter WASP-43b with Evidence of ${\mathrm{H}}_2\mathrm{O}$, but no evidence of Na or K
• A multiplicity study of transiting exoplanet host stars. II. Revised properties of transiting planetary systems with companions
• Refined physical properties and g',r',i',z',J,H,K transmission spectrum of WASP-23b from the ground
• LBT transmission spectroscopy of HAT-P-12b: confirmation of a cloudy atmosphere with no significant alkali features
• The Hubble PanCET Program: A Metal-rich Atmosphere for the Inflated Hot Jupiter HAT-P-41b
• Probing the atmosphere of a sub-Jovian planet orbiting a cool dwarf
• An enhanced slope in the transmission spectrum of the hot Jupiter WASP-104b
• ACCESS: Confirmation of no potassium in the atmosphere of WASP-31b

Cited by in corpus (9)

• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• LRG-BEASTS: sodium absorption and Rayleigh scattering in the atmosphere of WASP-94A b using NTT/EFOSC2
• Solar-to-supersolar sodium and oxygen absolute abundances for a "hot Saturn" orbiting a metal-rich star
• Why heterogeneous cloud particles matter: Iron-bearing species and cloud particle morphology affects exoplanet transmission spectra
• Detection of faculae in the transit and transmission spectrum of WASP-69b
• WASP-35 and HAT-P-30/WASP-51: re-analysis using TESS and ground-based transit photometry
• A precise blue-optical transmission spectrum from the ground: Evidence for haze in the atmosphere of WASP-74b
• LRG-BEASTS: Evidence for clouds in the transmission spectrum of HATS-46 b
• Low-resolution Transit Spectroscopy of Three Hot Jupiters Using the 2m Himalayan Chandra Telescope