ACCESS: A featureless optical transmission spectrum for WASP-19b from Magellan/IMACS

Abstract

The short period ($0.94$-day) transiting exoplanet WASP-19b is an exceptional target for transmission spectroscopy studies, due to its relatively large atmospheric scale-height ($\sim 500$ km) and equilibrium temperature ($\sim 2100$ K). Here we report on six precise spectroscopic Magellan/IMACS observations, five of which target the full optical window from $0.45-0.9\mu$m and one targeting the $0.4-0.55\mu$m blue-optical range. Five of these datasets are consistent with a transmission spectrum without any significant spectral features, while one shows a significant slope as a function of wavelength, which we interpret as arising from photospheric heterogeneities in the star. Coupled with HST/WFC3 infrared observations, our optical/near-infrared measurements point to the presence of high altitude clouds in WASP-19b's atmosphere in agreement with previous studies. Using a semi-analytical retrieval approach, considering both planetary and stellar spectral features, we find a water abundance consistent with solar for WASP-19b and strong evidence for sub-solar abundances for optical absorbers such as TiO and Na; no strong optical slope is detected, which suggests that if hazes are present, they are much weaker than previously suggested. In addition, two spot-crossing events are observed in our datasets and analyzed, including one of the first unambiguously detected bright spot-crossing events on an exoplanet host star.

arXiv comment20 pages (plus 5 for the Appendix), 17 figures, 5 tables. MNRAS, in press

References in corpus (83)

• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• The Man Behind the Curtain: X-rays Drive the UV through NIR Variability in the 2013 AGN Outburst in NGC 2617
• X-ray spectral modelling of the AGN obscuring region in the CDFS: Bayesian model selection and catalogue
• Detection of an Extrasolar Planet Atmosphere
• Bayes in the sky: Bayesian inference and model selection in cosmology
• The All-Sky Automated Survey for Supernovae (ASAS-SN) Light Curve Server v1.0
• batman: BAsic Transit Model cAlculatioN in Python
• The effects of snowlines on C/O in planetary atmospheres
• Fast and scalable Gaussian process modeling with applications to astronomical time series
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• Efficient, uninformative sampling of limb darkening coefficients for two-parameter laws
• Theoretical Transmission Spectra During Extrasolar Giant Planet Transits
• The ExoMol database: molecular line lists for exoplanet and other hot atmospheres
• Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• C/O ratio as a Dimension for Characterizing Exoplanetary Atmospheres
• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• The prevalence of dust on the exoplanet HD 189733b from Hubble and Spitzer observations
• Hubble Space Telescope Transmission Spectroscopy of the Exoplanet HD 189733b: High-altitude atmospheric haze in the optical and near-UV with STIS
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• A Precise Water Abundance Measurement for the Hot Jupiter WASP-43b
• Rayleigh scattering in the transit spectrum of HD 189733b
• The imprint of exoplanet formation history on observable present-day spectra of hot Jupiters
• The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets
• 3D mixing in hot Jupiter atmospheres. I. application to the day/night cold trap in HD 209458b
• Transitions in the cloud composition of hot Jupiters
• A simple method to estimate radial velocity variations due to stellar activity using photometry
• The Effect of Condensates on the Characterization of Transiting Planet Atmospheres with Transmission Spectroscopy
• Chemical consequences of the C/O ratio on hot Jupiters: Examples from WASP-12b,CoRoT-2b, XO-1b, and HD 189733b
• HD 209458b in New Light: Evidence of Nitrogen Chemistry, Patchy Clouds and Sub-Solar Water
• Bayesian model averaging: A systematic review and conceptual classification
• Water Vapour Absorption in the Clear Atmosphere of an exo-Neptune
• Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
• HST hot-Jupiter transmission spectral survey: detection of potassium in WASP-31b along with a cloud deck and Rayleigh scattering
• Detection of H2O and evidence for TiO/VO in an ultra hot exoplanet atmosphere
• Theory of Extrasolar Giant Planet Transits
• WASP-19b: the shortest period transiting exoplanet yet discovered
• HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
• HELIOS-K: An Ultrafast, Open-source Opacity Calculator for Radiative Transfer
• A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
• Detection of titanium oxide in the atmosphere of a hot Jupiter
• An HST Optical to Near-IR Transmission Spectrum of the Hot Jupiter WASP-19b: Detection of Atmospheric Water and Likely Absence of TiO
• Atmospheric Signatures of Giant Exoplanet Formation by Pebble Accretion
• Transmission Spectroscopy of the Hot-Jupiter WASP-12b from 0.7 to 5 microns
• A Theory for the Radius of the Transiting Giant Planet HD 209458b
• ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar Photosphere
• Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b
• Gran Telescopio Canarias OSIRIS Transiting Exoplanet Atmospheric Survey: Detection of potassium in XO-2b from narrowband spectrophotometry
• The theory of transmission spectra revisited: a semi-analytical method for interpreting WFC3 data and an unresolved challenge
• 3.6 and 4.5 $\mu$m $Spitzer$ Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b
• A Gemini ground-based transmission spectrum of WASP-29b: a featureless spectrum from 515 to 720nm
• The effect of stellar limb darkening values on the accuracy of the planet radii derived from photometric transit observations
• HST hot-Jupiter transmission spectral survey: Haze in the atmosphere of WASP-6b
• Impact of occultations of stellar active regions on transmission spectra: Can occultation of a plage mimic the signature of a blue sky?
• 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
• Transits and starspots in the WASP-19 planetary system
• On the orbit of the short-period exoplanet WASP-19b
• The Near-Infrared Transmission Spectra of TRAPPIST-1 Planets b, c, d, e, f, and g and Stellar Contamination in Multi-Epoch Transit Spectra
• A Ground-based Optical Transmission Spectrum of WASP-6b
• VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground
• Vibrational transition moments of CH${}_4$ from first principles
• GTC OSIRIS transiting exoplanet atmospheric survey: detection of sodium in XO-2b from differential long-slit spectroscopy
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• The optical transmission spectrum of the hot Jupiter HAT-P-32b: clouds explain the absence of broad spectral features?
• Accurate spectroscopic parameters of WASP planet host stars
• Limb-darkening and exoplanets II: Choosing the Best Law for Optimal Retrieval of Transit Parameters
• Physical properties, transmission and emission spectra of the WASP-19 planetary system from multi-colour photometry
• HST hot-Jupiter transmission spectral survey: Clear skies for cool Saturn WASP-39b
• spotrod: a semi-analytic model for transits of spotted stars
• Reliable inference of exoplanet light curve parameters using deterministic and stochastic systematics models
• A Characteristic Transmission Spectrum dominated by H${}_2$O applies to the majority of HST/WFC3 exoplanet observations
• Marginalising instrument systematics in HST WFC3 transit lightcurves
• VLT/FORS2 comparative transmission spectroscopy II: confirmation of a cloud-deck and Rayleigh scattering in WASP-31b, but no potassium?
• Transmission spectroscopy of the inflated exoplanet WASP-52b, and evidence for a bright region on the stellar surface
• 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
• Gemini/GMOS Transmission Spectral Survey: Complete Optical Transmission Spectrum of the hot Jupiter WASP-4b
• Regaining the FORS: optical ground-based transmission spectroscopy of the exoplanet WASP-19b with VLT+FORS2

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