Detection of ionized calcium in the atmosphere of the ultra-hot Jupiter KELT-9b

Abstract

With a day-side temperature in excess of 4500K, comparable to a mid-K-type star, KELT-9b is the hottest planet known. Its extreme temperature makes KELT-9b a particularly interesting test bed for investigating the nature and diversity of gas giant planets. We observed the transit of KELT-9b at high spectral resolution (R$\sim$94,600) with the CARMENES instrument on the Calar Alto 3.5-m telescope. Using these data, we detect for the first time ionized calcium (CaII triplet) absorption in the atmosphere of KELT-9b; this is the second time that CaII has been observed in a hot Jupiter. Our observations also reveal prominent H$\alpha$ absorption, confirming the presence of an extended hydrogen envelope around KELT-9b. We compare our detections with an atmospheric model and find that all four lines form between atmospheric temperatures of 6100 K and 8000 K and that the CaII lines form at pressures between 10 and 50 nbar while the H$\alpha$ line forms at a lower pressure ($\sim$6 nbar), higher up in the atmosphere. The altitude that the core of H$\alpha$ line forms is found to be $\sim$1.4 R${}_p$, well within the planetary Roche lobe ($\sim$1.9 R${}_p$). Therefore, rather than probing the escaping upper atmosphere directly, the H$\alpha$ line and the other observed Balmer and metal lines serve as atmospheric thermometers enabling us to probe the planet's temperature profile, thus energy budget.

arXiv commentAccepted to ApJL (December 11 2019), 11 pages, 3 figures, 2 tables, 2 Appendices (with 2 figures)

References in corpus (64)

• A new extensive library of PHOENIX stellar atmospheres and synthetic spectra
• Detection of Planetary Transits Across a Sun-like Star
• Detection of an Extrasolar Planet Atmosphere
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• The orbital motion, absolute mass, and high-altitude winds of exoplanet HD209458b
• ESPRESSO@VLT -- On-sky performance and first results
• Correcting systematic effects in a large set of photometric lightcurves
• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• Hubble Space Telescope Transmission Spectroscopy of the Exoplanet HD 189733b: High-altitude atmospheric haze in the optical and near-UV with STIS
• The signature of orbital motion from the dayside of the planet tau Bootis b
• The fast spin-rotation of a young extrasolar planet
• Spectroscopy Made Easy: Evolution
• A ground-based transmission spectrum of the super-Earth exoplanet GJ1214b
• Helium in the eroding atmosphere of an exoplanet
• A featureless transmission spectrum for the Neptune-mass exoplanet GJ 436b
• Metals in the Exosphere of the Highly Irradiated Planet WASP-12b
• Spectrally resolved detection of sodium in the atmosphere of HD189733b with the HARPS spectrograph
• Ground-based detection of an extended helium atmosphere in the Saturn-mass exoplanet WASP-69b
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Extremely Irradiated Hot Jupiters: Non-Oxide Inversions, H- Opacity, and Thermal Dissociation of Molecules
• Atomic iron and titanium in the atmosphere of the exoplanet KELT-9b
• Temporal variations in the evaporating atmosphere of the exoplanet HD 189733b
• Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
• A New Window into Escaping Exoplanet Atmospheres: 10830 Å Line of Helium
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• The Effect of Tidal Inflation Instability on the Mass and Dynamical Evolution of Extrasolar Planets with Ultra-Short Periods
• An extended hydrogen envelope of the extremely hot giant exoplanet KELT-9b
• 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
• An optical transmission spectrum for the ultra-hot Jupiter WASP-121b measured with the Hubble Space Telescope
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• The Peculiar Atmospheric Chemistry of KELT-9b
• High-resolution confirmation of an extended helium atmosphere around WASP-107b
• Three irradiated and bloated hot Jupiters: WASP-76b, WASP-82b & WASP-90b
• A Detection Of H-alpha In An Exoplanetary Exosphere
• 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
• Helium Absorption at 1083 nm from Extended Exoplanet Atmospheres: Dependence on Stellar Radiation
• Atmospheric dynamics and the variable transit of KELT-9 b
• Flux calibration of medium-resolution spectra from 300 nm to 2500 nm: Model reference spectra and telluric correction
• Decomposing the Iron Cross-Correlation Signal of the Ultra-Hot Jupiter WASP-76b in Transmission using 3D Monte-Carlo Radiative Transfer
• 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
• Search for water in a super-Earth atmosphere: High-resolution optical spectroscopy of 55 Cancri e
• Search for an exosphere in sodium and calcium in the transmission spectrum of exoplanet 55 Cancri e
• An inventory of atomic species in the atmosphere of WASP-121b using UVES high-resolution spectroscopy
• Non-local thermodynamic equilibrium effects determine the upper atmospheric temperature structure of the ultra-hot Jupiter KELT-9b
• Into the Storm: Diving into the winds of the ultra hot Jupiter WASP-76 b with HARPS and ESPRESSO
• Rapid escape of ultra-hot exoplanet atmospheres driven by Hydrogen Balmer absorption
• The GAPS Programme with HARPS-N at TNG XIX. Atmospheric Rossiter-McLaughlin effect and improved parameters of KELT-9b
• A Model of the H$\alpha$ and Na Transmission Spectrum of HD 189733b
• Investigating the physical properties of transiting hot Jupiters with the 1.5-m Kuiper Telescope
• Prospects for Characterizing the Haziest Sub-Neptune Exoplanets with High Resolution Spectroscopy
• XUV Radiation from A-stars: Implications for Ultra-hot Jupiters
• Investigation of the environment around close-in transiting exoplanets using CLOUDY
• Swift UVOT near-UV transit observations of WASP-121 b
• Near-UV and optical observations of the transiting exoplanet TrES-3b
• High-Resolution Transit Spectroscopy of Warm Saturns
• Near-UV transit photometry of HAT-P-32 b with the LBT: Silicate aerosols in the planetary atmosphere
• Characterising exo-ringsystems around fast-rotating stars using the Rossiter-McLaughlin effect
• The search for radio emission from exoplanets using LOFAR beam-formed observations: Jupiter as an exoplanet
• A ground-based NUV secondary eclipse observation of KELT-9b

Cited by in corpus (60)

• Detection of Fe I in the atmosphere of the ultra-hot Jupiter WASP-121b, and a new likelihood-based approach for Doppler-resolved spectroscopy
• Neutral Iron Emission Lines From The Day-side Of KELT-9b -- The GAPS Programme With HARPS-N At TNG XX
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• Mass loss rate and local thermodynamic state of KELT-9 b thermosphere from the hydrogen Balmer series
• Five key exoplanet questions answered via the analysis of 25 hot Jupiter atmospheres in eclipse
• Searching for Thermal Inversion Agents in the Transmission Spectrum of MASCARA-2b/KELT-20b: Detection of Neutral Iron and Ionised Calcium H$\&$K Lines
• Non-detection of TiO and VO in the atmosphere of WASP-121b using high-resolution spectroscopy
• Detection of Na, K, and H$\alpha$ absorption in the atmosphere of WASP-52b using ESPRESSO
• A temperature inversion with atomic iron in the ultra-hot dayside atmosphere of WASP-189b
• Exploring the atmospheric dynamics of the extreme ultra-hot Jupiter KELT-9b using TESS photometry
• An inventory of atomic species in the atmosphere of WASP-121b using UVES high-resolution spectroscopy
• High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
• Non-local thermodynamic equilibrium effects determine the upper atmospheric temperature structure of the ultra-hot Jupiter KELT-9b
• Detection of Fe\,{\sc i} Emission in the Day-side Spectrum of WASP-33b
• Cloud property trends in hot and ultra-hot giant gas planets (WASP-43b, WASP-103b, WASP-121b, HAT-P-7b, and WASP-18b)
• H$\alpha$ and He I absorption in HAT-P-32 b observed with CARMENES -- Detection of Roche lobe overflow and mass loss
• 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
• Confirmation of Iron Emission Lines and Non-detection of TiO on the Dayside of KELT-9b with MAROON-X
• Detection of iron emission lines and a temperature inversion on the dayside of the ultra-hot Jupiter KELT-20b
• High-resolution detection of neutral oxygen and non-LTE effects in the atmosphere of KELT-9b
• The Mantis Network III: Expanding the limits of chemical searches within ultra hot-Jupiters. New detections of Ca I, V I, Ti I, Cr I, Ni I, Sr II, Ba II, and Tb II in KELT-9 b
• High-resolution atmospheric retrievals of WASP-121b transmission spectroscopy with ESPRESSO: Consistent relative abundance constraints across multiple epochs and instruments
• Time-resolved rotational velocities in the upper atmosphere of WASP-33 b
• The Hubble WFC3 Emission Spectrum of the Extremely-Hot Jupiter, KELT-9b
• Mining the Ultra-Hot Skies of HAT-P-70b: Detection of a Profusion of Neutral and Ionized Species
• Detection of CO emission lines in the dayside atmospheres of WASP-33b and WASP-189b with GIANO
• A data-driven approach to constraining the atmospheric temperature structure of KELT-9b
• Detection of Ionized Calcium in the Atmosphere of the Ultra-Hot Jupiter WASP-76b
• Search for TiO and Optical Night-side Emission from the Exoplanet WASP-33b
• Auto-Differentiable Spectrum Model for High-Dispersion Characterization of Exoplanets and Brown Dwarfs
• Constraining planetary mass-loss rates by simulating Parker wind profiles with Cloudy
• The Colorado Ultraviolet Transit Experiment (CUTE) Mission Overview
• The obliquity and atmosphere of the ultra-hot Jupiter TOI-1431b (MASCARA-5b): A misaligned orbit and no signs of atomic ormolecular absorptions
• Modeling H$\alpha$ and He 10830 transmission spectrum of WASP-52b
• The Magellan/PFS Exoplanet Search: A 55-day period dense Neptune transiting the bright ($V=8.6$) star HD 95338
• The open-source sunbather code: modeling escaping planetary atmospheres and their transit spectra
• The GAPS programme at TNG. XLV. HI Balmer lines transmission spectroscopy and NLTE atmospheric modelling of the ultra-hot Jupiter KELT-20b/MASCARA-2b
• Transmission spectroscopy of the ultra-hot Jupiter MASCARA-4 b: Disentangling the hydrostatic and exospheric regimes of ultra-hot Jupiters
• Detection of Paschen $\beta$ absorption in the atmosphere of KELT-9 b: A new window into the atmospheres of ultra-hot Jupiters
• Neutral metals in the atmosphere of HD149026b
• Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b: III. Changing ionisation and the emergence of an ionosphere
• High-resolution atmospheric retrievals of WASP-76b transmission spectroscopy with ESPRESSO: Monitoring limb asymmetries across multiple transits
• High-resolution Emission Spectroscopy of the Ultrahot Jupiter KELT-9b: Little Variation in Day- and Nightside Emission Line Contrasts
• A warm super-Neptune around the G-dwarf star TOI-1710 revealed with TESS, SOPHIE and HARPS-N
• Non-Local Thermodynamic Equilibrium Transmission Spectrum Modelling of HD209458b
• The GAPS programme at TNG: TBD. Studies of atmospheric FeII winds in ultra-hot Jupiters KELT-9b and KELT-20b using HARPS-N spectrograph
• Searching for NLTE effects in the high-resolution transmission spectrum of WASP-121 b with Cloudy for Exoplanets
• The GAPS programme at TNG LX Atmospheric characterisation of KELT-9 b via single-line analysis: Detection of six H I Balmer lines, Na I, Ca I, Ca II, Fe I, Fe II, Mg I, Ti II, Sc II, and Cr II
• Multi-epoch detections of the extended atmosphere and transmission spectra of KELT-9b with a 1.5 m telescope
• Probing the atmosphere of HD189733b with the Na I and K I lines
• Extreme winds on the emerging dayside of an ultrahot Jupiter
• A Time-Resolved High-Resolution Spectroscopic Analysis of Ionized Calcium and Dynamical Processes in the Ultra-Hot Jupiter HAT-P-70 b
• KELT-9 and its ultra-hot Jupiter: stellar parameters, composition, and planetary pollution
• NLTE atmospheric modelling of the ultra-hot Jupiter WASP-178b and comparison with UV and optical observations
• Generic Models for Disk-Resolved and Disk-Integrated Phase Dependent Linear Polarization of Light Reflected from Exoplanets
• Open Source High-Resolution Exoplanet Atmosphere Retrievals with POSEIDON
• Ground-Based Reconnaissance Observations of 21 Exoplanet Atmospheres with the Exoplanet Transmission Spectroscopy Imager
• CARMENES detection of the CaII infrared triplet and possible evidence of HeI in the atmosphere of WASP-76b
• Day-side Fe I Emission, Day-Night Brightness Contrast and Phase Offset of the Exoplanet WASP-33b