Time-resolved rotational velocities in the upper atmosphere of WASP-33 b

Abstract

While steady empirical progress has been made in understanding the structure and composition of hot planet atmospheres, direct measurements of velocity signatures, including winds, rotation, and jets, have lagged behind. Quantifying atmospheric dynamics of hot planets is critical to a complete understanding of their atmospheres and such measurements may even illuminate other planetary properties, such as magnetic field strengths. In this manuscript we present the first detection of the Balmer lines H$\alpha$ and H$\beta$ in the atmosphere of the ultra-hot Jupiter WASP-33 b. Using atmospheric models which include the effects of atmospheric dynamics, we show that the shape of the average Balmer line transmission spectrum is consistent with rotational velocities in the planet's thermosphere of $v_{\text{rot}}=10.1_{-1.0}^{+0.8}$ km s${}^{-1}$. We also measure a low-significance day-to-night side velocity shift of $-4.6_{-3.4}^{+3.4}$ km s${}^{-1}$ in the transmission spectrum which is naturally explained by a global wind across the planet's terminator. In a separate analysis the time-resolved velocity centroids of individual transmission spectra show unambiguous evidence of rotation, with a best-fit velocity of $10.0_{-2.0}^{+2.4}$ km s${}^{-1}$, consistent with the value of $v_{\text{rot}}$ derived from the shape of the average Balmer line transmission spectrum. Our observations and analysis confirm the power of high signal-to-noise, time-resolved transmission spectra to measure the velocity structures in exoplanet atmospheres. The large rotational and wind velocities we measure highlight the need for more detailed 3D global climate simulations of the rarefied upper-atmospheres of ultra-hot gas giants.

arXiv commentAccepted to AAS Journals. This re-submission updates the original version with changes made during the referee process. None of the changes affect the conclusions of the paper, although a few specific numbers have new values. We also note that during the review process we became aware of a contemporaneous detection of the Balmer lines in WASP-33 b's atmosphere by Yan et al. 2020, A&A, 645, A22

References in corpus (98)

• emcee: The MCMC Hammer
• Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 20945
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• Molecfit: A general tool for telluric absorption correction. I. Method and application to ESO instruments
• EXOFAST: A fast exoplanetary fitting suite in IDL
• Atmospheric Circulation and Tides of "51Peg b-like" Planets
• A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
• Molecfit: A general tool for telluric absorption correction II. Quantitative evaluation on ESO-VLT X-Shooter spectra
• The fast spin-rotation of a young extrasolar planet
• Equatorial superrotation on tidally locked exoplanets
• Spectroscopy Made Easy: Evolution
• Helium in the eroding atmosphere of an exoplanet
• From thermal dissociation to condensation in the atmospheres of ultra hot Jupiters: WASP-121b in context
• 3.6 and 4.5 Micron Phase Curves and Evidence for Non-Equilibrium Chemistry in the Atmosphere of Extrasolar Planet HD 189733b
• Spectrally resolved detection of sodium in the atmosphere of HD189733b with the HARPS spectrograph
• Nightside condensation of iron in an ultra-hot giant exoplanet
• Line-profile tomography of exoplanet transits -- II. A gas-giant planet transiting a rapidly-rotating A5 star
• Retrieving Temperatures and Abundances of Exoplanet Atmospheres with High-Resolution Cross-Correlation Spectroscopy
• An ultrahot gas-giant exoplanet with a stratosphere
• Atomic iron and titanium in the atmosphere of the exoplanet KELT-9b
• Rotation and winds of exoplanet HD 189733 b measured with high-dispersion transmission spectroscopy
• Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
• Aerosol Composition of Hot Giant Exoplanets Dominated by Silicates and Hydrocarbon Hazes
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra II: A Uniform Analysis of Eight Planets and Their C to O Ratios
• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• Doppler Signatures of the Atmospheric Circulation on Hot Jupiters
• Hubble PanCET: An extended upper atmosphere of neutral hydrogen around the warm Neptune GJ 3470 b
• An extended hydrogen envelope of the extremely hot giant exoplanet KELT-9b
• A consistent retrieval analysis of 10 Hot Jupiters observed in transmission
• Three Dimensional Modeling of Hot Jupiter Atmospheric Flows
• The HST PanCET Program: Exospheric Mg II and Fe II in the Near-UV transmission spectrum of WASP-121b using Jitter Decorrelation
• Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b
• Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets
• Three-Dimensional Atmospheric Circulation Models of HD 189733b and HD 209458b with Consistent Magnetic Drag and Ohmic Dissipation
• Spatially resolved eastward winds and rotation of HD 189733b
• Simulating the escaping atmospheres of hot gas planets in the solar neighborhood
• No Thermal Inversion and a Solar Water Abundance for the Hot Jupiter HD209458b from HST WFC3 Emission Spectroscopy
• PEPSI: The high-resolution echelle spectrograph and polarimeter for the Large Binocular Telescope
• High-Resolution Spectroscopic Detection of TiO and Stratosphere in the Day-side of WASP-33b
• The Atmospheric Circulation of the Hot Jupiter WASP-43b: Comparing Three-Dimensional Models to Spectrophotometric Data
• Detection of He I $\lambda 10830$ Å absorption on HD 189733 b with CARMENES high-resolution transmission spectroscopy
• Atmospheric escape from HD 189733b observed in HI Lyman-alpha: detailed analysis of HST/STIS September 2011 observations
• Atmospheric Rossiter-McLaughlin effect and transmission spectroscopy of WASP-121b with ESPRESSO
• 3.6 and 4.5 $\mu$m $Spitzer$ Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b
• Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX
• Constraining High Speed Winds in Exoplanet Atmospheres Through Observations of Anomalous Doppler Shifts During Transit
• The long egress of GJ~436b's giant exosphere
• Magnetic field strengths of hot Jupiters from signals of star-planet interactions
• High-resolution confirmation of an extended helium atmosphere around WASP-107b
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) III. Atmospheric structure of the misaligned ultra-hot Jupiter WASP-121b
• Ionized calcium in the atmospheres of two ultra-hot exoplanets WASP-33b and KELT-9b
• Ground-based near-UV observations of 15 transiting exoplanets: Constraints on their atmospheres and no evidence for asymmetrical transits
• The High-Resolution Transmission Spectrum of HD 189733b Interpreted with Atmospheric Doppler Shifts from Three-Dimensional General Circulation Models
• The Featureless Transmission Spectra of Two Super-Puff Planets
• Detection of sodium in the atmosphere of WASP-69b
• Atmospheric dynamics and the variable transit of KELT-9 b
• Spitzer Phase Curves of KELT-1b and the Signatures of Nightside Clouds in Thermal Phase Observations
• Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series
• Detection of neutral atomic species in the ultra-hot jupiter WASP-121b
• The center-to-limb variation across the Fraunhofer lines of HD 189733; Sampling the stellar spectrum using a transiting planet
• PEPSI deep spectra. I. The Sun-as-a-star
• Searching for Thermal Inversion Agents in the Transmission Spectrum of MASCARA-2b/KELT-20b: Detection of Neutral Iron and Ionised Calcium H$\&$K Lines
• The effect of the stellar absorption line centre-to-limb variation on exoplanet transmission spectrum observations
• Detection of Na, K, and H$\alpha$ absorption in the atmosphere of WASP-52b using ESPRESSO
• Thermal Processes Governing Hot-Jupiter Radii
• Detection of ionized calcium in the atmosphere of the ultra-hot Jupiter KELT-9b
• Measurement of the Nodal Precession of WASP-33 b via Doppler Tomography
• Equatorial anti-rotating day side wind flow in WASP-43b elicited by deep wind jets?
• Search for an exosphere in sodium and calcium in the transmission spectrum of exoplanet 55 Cancri e
• WASP-33: The first delta Scuti exoplanet host star
• A temperature inversion with atomic iron in the ultra-hot dayside atmosphere of WASP-189b
• Wind of Change: retrieving exoplanet atmospheric winds from high-resolution spectroscopy
• Exploring the atmospheric dynamics of the extreme ultra-hot Jupiter KELT-9b using TESS photometry
• Detection of Fe I and Fe II in the atmosphere of MASCARA-2b using a cross-correlation method
• A transition between the hot and the ultra-hot Jupiter atmospheres
• Hydrogen and Sodium Absorption in the Optical Transmission Spectrum of WASP-12b
• Obliquity Constraints on an Extrasolar Planetary-Mass Companion
• A decade of H$\alpha$ transits for HD 189733 b: stellar activity versus absorption in the extended atmosphere
• Detection of Fe\,{\sc i} Emission in the Day-side Spectrum of WASP-33b
• Rapid escape of ultra-hot exoplanet atmospheres driven by Hydrogen Balmer absorption
• Limits on Clouds and Hazes for the TRAPPIST-1 Planets
• The effects of stellar activity on optical high-resolution exoplanet transmission spectra
• Temporal Variability in Hot Jupiter Atmospheres
• An optical transmission spectrum of the ultra-hot Jupiter WASP-33b. First indication of AlO in an exoplanet
• TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star
• A Model of the H$\alpha$ and Na Transmission Spectrum of HD 189733b
• Precise photometric transit follow-up observations of five close-in exoplanets : update on their physical properties
• Neutral Cr and V in the atmosphere of ultra hot jupiter WASP-121 b
• Detection of the hydrogen Balmer lines in the ultra-hot Jupiter WASP-33b
• Pulsation analysis and its impact on primary transit modeling in WASP-33
• Excitation of Planetary Obliquities Through Planet-Disk Interactions
• Hubble PanCET: An isothermal day-side atmosphere for the bloated gas-giant HAT-P-32Ab
• Classical and relativistic node precessional effects in WASP-33b and perspectives for detecting them
• The potassium absorption on HD189733b and HD209458b
• Doppler Tomographic Measurement of the Nodal Precession of WASP-33b
• EPIC 203868608: A low-mass quadruple star system in the Upper Scorpius OB association

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• Carbon monoxide emission lines reveal an inverted atmosphere in the ultra hot Jupiter WASP-33 b consistent with an eastward hot spot
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• Detection of the hydrogen Balmer lines in the ultra-hot Jupiter WASP-33b
• Time-resolved transmission spectroscopy of the ultra-hot Jupiter WASP-189 b
• Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b
• Mining the Ultra-Hot Skies of HAT-P-70b: Detection of a Profusion of Neutral and Ionized Species
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• Detection of CO emission lines in the dayside atmospheres of WASP-33b and WASP-189b with GIANO
• Keck/KPIC Emission Spectroscopy of WASP-33b
• Silicon in the dayside atmospheres of two ultra-hot Jupiters
• The PEPSI Exoplanet Transit Survey (PETS) I: Investigating the presence of a silicate atmosphere on the super-Earth 55 Cnc e
• Variable and super-sonic winds in the atmosphere of an ultra-hot giant planet
• Vertical structure of an exoplanet's atmospheric jet stream
• Modeling H$\alpha$ and He 10830 transmission spectrum of WASP-52b
• The GAPS Programme with HARPS-N at TNG. XXXI. The WASP-33 system revisited with HARPS-N
• TOI-2046b, TOI-1181b and TOI-1516b, three new hot Jupiters from \textit{TESS}: planets orbiting a young star, a subgiant and a normal star
• Dynamics and Clouds in Planetary Atmospheres from Telescopic Observations
• Nodal Precession and Tidal Evolution of Two Hot-Jupiters: WASP-33 b and KELT-9 b
• Limits on the Auroral Generation of H${}_3^{+}$ in Brown Dwarf and Extrasolar Giant Planet Atmospheres with Keck/NIRSPEC
• Shallowness of circulation in hot Jupiters -- Advancing the Ohmic dissipation model
• Characterization of exoplanetary atmospheres with SLOPpy
• Titanium chemistry of WASP-121 b with ESPRESSO in 4-UT mode
• The atmospheric composition of the ultra-hot Jupiter WASP-178 b observed with ESPRESSO
• Multi-epoch detections of the extended atmosphere and transmission spectra of KELT-9b with a 1.5 m telescope
• Spectral signature of atmospheric winds in high resolution transit observations
• The GAPS programme at TNG LXVI. A homogeneous search for Na i and its possible variability in ten gas giant exoplanets
• The effects of stellar gravity darkening on high-resolution transmission spectra
• Modelling helium in exoplanet atmospheres. A revised network with photoelectron-driven processes
• Magnetic field strengths of hot giant exoplanets consistent with Solar System values
• CHEOPS observations confirm nodal precession in the WASP-33 system