ACCESS & LRG-BEASTS: a precise new optical transmission spectrum of the ultrahot Jupiter WASP-103b

Abstract

We present a new ground-based optical transmission spectrum of the ultrahot Jupiter WASP-103b ($T_{eq}=2484$K). Our transmission spectrum is the result of combining five new transits from the ACCESS survey and two new transits from the LRG-BEASTS survey with a reanalysis of three archival Gemini/GMOS transits and one VLT/FORS2 transit. Our combined 11-transit transmission spectrum covers a wavelength range of 3900--9450A with a median uncertainty in the transit depth of 148 parts-per-million, which is less than one atmospheric scale height of the planet. In our retrieval analysis of WASP-103b's combined optical and infrared transmission spectrum, we find strong evidence for unocculted bright regions ($4.3\sigma$) and weak evidence for H${}_2$O ($1.9\sigma$), HCN ($1.7\sigma$), and TiO ($2.1\sigma$), which could be responsible for WASP-103b's observed temperature inversion. Our optical transmission spectrum shows significant structure that is in excellent agreement with the extensively studied ultrahot Jupiter WASP-121b, for which the presence of VO has been inferred. For WASP-103b, we find that VO can only provide a reasonable fit to the data if its abundance is implausibly high and we do not account for stellar activity. Our results highlight the precision that can be achieved by ground-based observations and the impacts that stellar activity from F-type stars can have on the interpretation of exoplanet transmission spectra.

33 pages, 17 figures, 7 tables. Accepted for publication in AJ

References in corpus (43)

• The NumPy array: a structure for efficient numerical computation
• petitRADTRANS: a Python radiative transfer package for exoplanet characterization and retrieval
• Atomic and Molecular Opacities for Brown Dwarf and Giant Planet Atmospheres
• Water Vapor in the Spectrum of the Extrasolar Planet HD 189733b: 1. the Transit
• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• An ultrahot gas-giant exoplanet with a stratosphere
• 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
• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• ACCESS I: An Optical Transmission Spectrum of GJ 1214b Reveals a Heterogeneous Stellar Photosphere
• The Transit Light Source Effect II: The Impact of Stellar Heterogeneity on Transmission Spectra of Planets Orbiting Broadly Sun-like Stars
• Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO
• Friends of Hot Jupiters. IV. Stellar companions beyond 50 AU might facilitate giant planet formation, but most are unlikely to cause Kozai-Lidov migration
• Impact of occultations of stellar active regions on transmission spectra: Can occultation of a plage mimic the signature of a blue sky?
• Exploring Biases of Atmospheric Retrievals in Simulated JWST Transmission Spectra of Hot Jupiters
• Ionized calcium in the atmospheres of two ultra-hot exoplanets WASP-33b and KELT-9b
• VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground
• Evidence for a Dayside Thermal Inversion and High Metallicity for the Hot Jupiter WASP-18b
• An emission spectrum for WASP-121b measured across the 0.8-1.1 micron wavelength range using the Hubble Space Telescope
• VLT/FORS2 comparative transmission spectroscopy II: confirmation of a cloud-deck and Rayleigh scattering in WASP-31b, but no potassium?
• The Influence of Host Star Spectral Type on Ultra-Hot Jupiter Atmospheres
• Confirmation of water emission in the dayside spectrum of the ultrahot Jupiter WASP-121b
• Detection of Fe\,{\sc i} Emission in the Day-side Spectrum of WASP-33b
• High-precision photometry by telescope defocussing. VII. The ultra-short period planet WASP-103
• Signs of strong Na and K absorption in the transmission spectrum of WASP-103b
• Neutral Cr and V in the atmosphere of ultra hot jupiter WASP-121 b
• Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope
• Detection of the hydrogen Balmer lines in the ultra-hot Jupiter WASP-33b
• LRG-BEASTS III: Ground-based transmission spectrum of the gas giant orbiting the cool dwarf WASP-80
• Near-Infrared Emission Spectrum of WASP-103b using Hubble Space Telescope/Wide Field Camera 3
• The Hubble WFC3 Emission Spectrum of the Extremely-Hot Jupiter, KELT-9b
• Contamination from a nearby star cannot explain the anomalous transmission spectrum of the ultra-short period giant planet WASP-103b
• High-precision multi-wavelength eclipse photometry of the ultra-hot gas giant exoplanet WASP-103 b
• SALT observations of the Chromospheric Activity of Transiting Planet Hosts: Mass Loss and Star Planet Interactions
• 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
• ACCESS: Ground-based Optical Transmission Spectroscopy of the Hot Jupiter WASP-4b
• Evidence of a Clear Atmosphere for WASP-62b: the Only Known Transiting Gas Giant in the JWST Continuous Viewing Zone
• LRG-BEASTS: Ground-based Detection of Sodium and a Steep Optical Slope in the Atmosphere of the Highly Inflated Hot-Saturn WASP-21b
• ACCESS: Confirmation of no potassium in the atmosphere of WASP-31b
• ACCESS: An optical transmission spectrum of the high-gravity, hot Jupiter HAT-P-23b

Cited by in corpus (42)

• Early Release Science of the exoplanet WASP-39b with JWST NIRSpec PRISM
• Early Release Science of the Exoplanet WASP-39b with JWST NIRSpec G395H
• Identification of carbon dioxide in an exoplanet atmosphere
• High Tide or Riptide on the Cosmic Shoreline? A Water-Rich Atmosphere or Stellar Contamination for the Warm Super-Earth GJ~486b from JWST Observations
• A JWST transmission spectrum of a nearby Earth-sized exoplanet
• Sulphur dioxide in the mid-infrared transmission spectrum of WASP-39b
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• Near-Infrared Transmission Spectroscopy of HAT-P-18b with NIRISS: Disentangling Planetary and Stellar Features in the Era of JWST
• A comparison of chemical models of exoplanet atmospheres enabled by TauREx 3.1
• On Atmospheric Retrievals of Exoplanets with Inhomogeneous Terminators
• The First Near-Infrared Transmission Spectrum of HIP 41378 f, a Low-Mass Temperate Jovian World in a Multi-Planet System
• Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy
• LRG-BEASTS: sodium absorption and Rayleigh scattering in the atmosphere of WASP-94A b using NTT/EFOSC2
• Can 1D radiative equilibrium models of faculae be used for calculating contamination of transmission spectra?
• Spectral variability of photospheric radiation due to faculae II: Facular contrasts for cool main-sequence stars
• Using JWST transits and occultations to determine $\sim 1\%$ stellar radii and temperatures of low-mass stars
• BOWIE-ALIGN: JWST reveals hints of planetesimal accretion and complex sulphur chemistry in the atmosphere of the misaligned hot Jupiter WASP-15b
• On spectroscopic phase-curve retrievals: H2 dissociation and thermal inversion in the atmosphere of the ultra-hot Jupiter WASP-103 b
• ACCESS: Confirmation of a Clear Atmosphere for WASP-96b and a Comparison of Light Curve Detrending Techniques
• ThERESA: Three-Dimensional Eclipse Mapping with Application to Synthetic JWST Data
• A new method to measure the spectra of transiting exoplanet atmospheres using multi-object spectroscopy
• Homogeneous Transit Timing Analyses of Ten Exoplanet Systems
• BOWIE-ALIGN: A JWST comparative survey of aligned vs misaligned hot Jupiters to test the dependence of atmospheric composition on migration history
• Detection of TiO and VO in the atmosphere of WASP-121b and Evidence for its temporal variation
• Tracing the formation and migration history: molecular signatures in the atmosphere of misaligned hot Jupiter WASP-94Ab using JWST NIRSpec/G395H
• Stellar Models Also Limit Exoplanet Atmosphere Studies in Emission
• Planet-star interactions with precise transit timing. III. Entering the regime of dynamical tides
• Detection of faculae in the transit and transmission spectrum of WASP-69b
• Seasonal Changes in the Atmosphere of HD 80606b Observed with JWST's NIRSpec/G395H
• A precise blue-optical transmission spectrum from the ground: Evidence for haze in the atmosphere of WASP-74b
• Tentative detection of titanium oxide in the atmosphere of WASP-69 b with a 4m ground-based telescope
• LRG-BEASTS: Evidence for clouds in the transmission spectrum of HATS-46 b
• Thermal Emission from the hot Jupiter WASP-103b in J and Ks Bands
• Possible Evidence for the Presence of Volatiles on the Warm Super-Earth TOI-270 b
• ACCESS: Tentative detection of H${}_2$O in the ground-based optical transmission spectrum of the low-density hot Saturn HATS-5b
• The Magnetically Induced Radial Velocity Variation of Gliese 341 and an Upper Limit to the Mass of Its Transiting Earth-sized Planet
• Rapid characterization of exoplanet atmospheres with the Exoplanet Transmission Spectroscopy Imager (ETSI)
• UV Absorption by Silicate Cloud Precursors in Ultra-hot Jupiter WASP-178b
• Ground-Based Reconnaissance Observations of 21 Exoplanet Atmospheres with the Exoplanet Transmission Spectroscopy Imager
• The effect of JWST/NIRSpec data reduction on the retrieval of WASP-39b atmospheric properties
• A new method to correct for host star variability in multi-epoch observations of exoplanet transmission spectra
• Using observations of escaping H/He to constrain the atmospheric composition of sub-Neptunes