Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) I. Detection of hot neutral sodium at high altitudes on WASP-49b

Abstract

High-resolution optical spectroscopy during the transit of HD 189733b, a prototypical hot Jupiter, allowed the resolution of the Na I D sodium lines in the planet, giving access to the extreme conditions of the planet upper atmosphere. We have undertaken HEARTS, a spectroscopic survey of exoplanet upper atmospheres, to perform a comparative study of hot gas giants and determine how stellar irradiation affect them. Here, we report on the first HEARTS observations of the hot Saturn-mass planet WASP-49b. We observed the planet with the HARPS high-resolution spectrograph at ESO 3.6m telescope. We collected 126 spectra of WASP-49, covering three transits of WASP-49b. We analyzed and modeled the planet transit spectrum, while paying particular attention to the treatment of potentially spurious signals of stellar origin. We spectrally resolve the Na I D lines in the planet atmosphere and show that these signatures are unlikely to arise from stellar contamination. The large contrasts of $2.0\pm 0.5\%$ (D${}_2$) and $1.8\pm 0.7\%$ (D${}_1$) require the presence of hot neutral sodium ($2,950_{-500}^{+400}$ K) at high altitudes ($\sim$1.5 planet radius or $\sim$45,000 km). From estimating the cloudiness index of WASP-49b, we determine its atmosphere to be cloud free at the altitudes probed by the sodium lines. WASP-49b is close to the border of the evaporation desert and exhibits an enhanced thermospheric signature with respect to a farther-away planet such as HD 189733b.

arXiv commentAccepted for publication in A&A. 14 pages

References in corpus (57)

• Analytic Lightcurves for Planetary Transit Searches
• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• 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
• Theoretical Transmission Spectra During Extrasolar Giant Planet Transits
• Obliquities of Hot Jupiter host stars: Evidence for tidal interactions and primordial misalignments
• The CORALIE survey for southern extra-solar planets VII. Two short-period Saturnian companions to HD108147 and HD168746
• A giant comet-like cloud of hydrogen escaping the warm Neptune-mass exoplanet GJ 436b
• Sodium Absorption From the Exoplanetary Atmosphere of HD189733b Detected in the Optical Transmission Spectrum
• Spin-orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters
• Accurate, Empirical Radii and Masses of Planets and their Host Stars with Gaia Parallaxes
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• Dearth of short-period Neptunian exoplanets - a desert in period-mass and period-radius planes
• Spectrally resolved detection of sodium in the atmosphere of HD189733b with the HARPS spectrograph
• Ground-based detection of sodium in the transmission spectrum of exoplanet HD209458b
• Atmospheric Escape from Hot Jupiters
• A diagram for the evaporation status of extrasolar planets
• Temporal variations in the evaporating atmosphere of the exoplanet HD 189733b
• Rotation and winds of exoplanet HD 189733 b measured with high-dispersion transmission spectroscopy
• The escape of heavy atoms from the ionosphere of HD209458b. I. A photochemical-dynamical model of the thermosphere
• PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance
• HST hot Jupiter Transmission Spectral Survey: A detection of Na and strong optical absorption in HAT-P-1b
• Temperature-Pressure Profile of the hot Jupiter HD 189733b from HST Sodium Observations: Detection of Upper Atmospheric Heating
• HST/STIS Optical Transit Transmission Spectra of the hot-Jupiter HD209458b
• Spatially resolved eastward winds and rotation of HD 189733b
• The Rossiter-McLaughlin effect reloaded: Probing the 3D spin-orbit geometry, differential stellar rotation, and the spatially-resolved stellar spectrum of star-planet systems
• WASP-8b: a retrograde transiting planet in a multiple system
• The transmission spectrum of Earth-size transiting planets
• WASP-42 b and WASP-49 b: two new transiting sub-Jupiters
• Magnesium in the atmosphere of the planet HD209458b: Observations of the thermosphere-exosphere transition region
• Mass-loss rates for transiting exoplanets
• The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles
• Determining atmospheric conditions at the terminator of the hot-Jupiter HD209458b
• VLT FORS2 comparative transmission spectroscopy: Detection of Na in the atmosphere of WASP-39b from the ground
• The escape of heavy atoms from the ionosphere of HD209458b. II. Interpretation of the observations
• A Cloudiness Index for Transiting Exoplanets Based on the Sodium and Potassium Lines: Tentative Evidence for Hotter Atmospheres Being Less Cloudy at Visible Wavelengths
• Absorbing gas around the WASP-12 planetary system
• The center-to-limb variation across the Fraunhofer lines of HD 189733; Sampling the stellar spectrum using a transiting planet
• Rossiter--McLaughlin models and their effect on estimates of stellar rotation, illustrated using six WASP systems
• Ground-based detection of Calcium and possibly Scandium and Hydrogen in the atmosphere of HD 209458b
• A Survey of Alkali Line Absorption in Exoplanetary Atmospheres
• HST hot-Jupiter transmission spectral survey: Clear skies for cool Saturn WASP-39b
• The upper atmosphere of the exoplanet HD209458b revealed by the sodium D lines: Temperature-pressure profile, ionization layer, and thermosphere
• Evidence for a lost population of close-in exoplanets
• Transmission spectroscopy of the sodium 'D' doublet in WASP-17b with the VLT
• Search for an exosphere in sodium and calcium in the transmission spectrum of exoplanet 55 Cancri e
• The GTC exoplanet transit spectroscopy survey I: OSIRIS transmission spectroscopy of the short period planet WASP-43b
• FORS2 observes a multi-epoch transmission spectrum of the hot Saturn-mass exoplanet WASP-49b
• The origin of the excess transit absorption in the HD 189733 system: planet or star?
• Exoplanetary atmospheric sodium revealed by the orbital motion. Narrow-band transmission spectroscopy of HD 189733b with UVES
• Analytical determination of orbital elements using Fourier analysis. I. The radial velocity case
• Detection of sodium absorption in WASP-17b with Magellan
• A Non-isothermal Theory for Interpreting Sodium Lines in Transmission Spectra of Exoplanets
• Refined architecture of the WASP-8 system: a cautionary tale for traditional Rossiter-McLaughlin analysis
• Defocussed Transmission Spectroscopy: A potential detection of sodium in the atmosphere of WASP-12b
• Corrigendum to "The upper atmosphere of the exoplanet HD209458b revealed by the sodium D lines: Temperature-pressure profile, ionization layer and thermosphere" [2011, A&A, 527, A110]

Cited by in corpus (85)

• ESPRESSO@VLT -- On-sky performance and first results
• Exoplanetary Atmospheres: Key Insights, Challenges and Prospects
• Extremely Irradiated Hot Jupiters: Non-Oxide Inversions, H- Opacity, and Thermal Dissociation of Molecules
• Spectrally resolved helium absorption from the extended atmosphere of a warm Neptune-mass exoplanet
• A spectral survey of an ultra-hot Jupiter: Detection of metals in the transmission spectrum of KELT-9 b
• Stellar obliquities in exoplanetary systems
• Atmospheric characterization of the ultra-hot Jupiter MASCARA-2b/KELT-20b
• 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
• An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet
• GENESIS: New Self-Consistent Models of Exoplanetary Spectra
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) - II. A broadened sodium feature on the ultra-hot giant WASP-76b
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) III. Atmospheric structure of the misaligned ultra-hot Jupiter WASP-121b
• Hot Jupiters: Origins, Structure, Atmospheres
• Detection of sodium in the atmosphere of WASP-69b
• The Rossiter-McLaughlin effect in Exoplanet Research
• Atmospheric dynamics and the variable transit of KELT-9 b
• 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
• Search for water vapor in the high-resolution transmission spectrum of HD189733b in the visible
• Na I and H$\alpha$ absorption features in the atmosphere of MASCARA-2b/KELT-20b
• Searching for Thermal Inversion Agents in the Transmission Spectrum of MASCARA-2b/KELT-20b: Detection of Neutral Iron and Ionised Calcium H$\&$K Lines
• Detection of Na, K, and H$\alpha$ absorption in the atmosphere of WASP-52b using ESPRESSO
• A He I upper atmosphere around the warm Neptune GJ 3470b
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• Wind of Change: retrieving exoplanet atmospheric winds from high-resolution spectroscopy
• The atmosphere of HD 209458b seen with ESPRESSO. No detectable planetary absorptions at high resolution
• Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets
• Into the Storm: Diving into the winds of the ultra hot Jupiter WASP-76 b with HARPS and ESPRESSO
• High-resolution Transmission Spectroscopy of MASCARA-2 b with EXPRES
• Is there NaI in the atmosphere of HD 209458b? Effect of the centre-to-limb variation and Rossiter-McLaughlin effect in transmission spectroscopy studies
• The effects of stellar activity on optical high-resolution exoplanet transmission spectra
• Combining low- to high-resolution transit spectroscopy of HD 189733b. Linking the troposphere and the thermosphere of a hot gas giant
• The GTC exoplanet transit spectroscopy survey. VII. Detection of sodium in WASP-52b's cloudy atmosphere
• ExoClock project II: A large-scale integrated study with 180 updated exoplanet ephemerides
• A Jovian planet in an eccentric 11.5 day orbit around HD1397 discovered by TESS
• Interpreting High-Resolution Spectroscopy of Exoplanets Using Cross-Correlations and Supervised Machine Learning
• A Spectral Survey of WASP-19b with ESPRESSO
• Keck/NIRSPEC studies of He I in the atmospheres of two inflated hot gas giants orbiting K dwarfs: WASP-52b and WASP-177b
• Alkaline Exospheres of Exoplanet Systems: Evaporative Transmission Spectra
• LRG-BEASTS III: Ground-based transmission spectrum of the gas giant orbiting the cool dwarf WASP-80
• The SOPHIE search for northern extrasolar planets. XIV. A temperate ($T_{\mathrm{eq}}\sim 300$ K) super-earth around the nearby star Gliese 411
• High-resolution transmission spectroscopy of four hot inflated gas giant exoplanets
• 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
• DREAM II. The spin-orbit angle distribution of close-in exoplanets under the lens of tides
• The HST PanCET Program: Hints of Na I & Evidence of a Cloudy Atmosphere for the Inflated Hot Jupiter WASP-52b
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) VI. Non-detection of sodium with HARPS on the bloated super-Neptune WASP-127b
• ExoClock Project: An open platform for monitoring the ephemerides of Ariel targets with contributions from the public
• Revisiting the potassium feature of WASP-31b at high-resolution
• A data-driven approach to constraining the atmospheric temperature structure of KELT-9b
• A survey of sodium absorption in ten giant exoplanets with high-resolution transmission spectroscopy
• The GTC exoplanet transit spectroscopy survey XI. Possible detection of Rayleigh scattering in the atmosphere of the Saturn-mass planet WASP-69b
• Diagnosing aerosols in extrasolar giant planets with cross-correlation function of water bands
• Precise masses for the transiting planetary system HD 106315 with HARPS
• How Much Information Does the Sodium Doublet Encode? Retrieval Analysis of Non-LTE Sodium Lines at Low and High Spectral Resolutions
• Detection of Na in WASP-21b's lower and upper atmosphere
• Two long-period transiting exoplanets on eccentric orbits: NGTS-20 b (TOI-5152 b) and TOI-5153 b
• MASCARA-4 b/bRing-1b - A retrograde hot Jupiter around the bright A3V star HD 85628
• Stellar contributions to the line profiles of high-resolution transmission spectra of exoplanets
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) VII. Detection of sodium on the long-transiting inflated sub-Saturn KELT-11 b
• Assessing telluric correction methods for Na detections with high-resolution exoplanet transmission spectroscopy
• Radio-Loud Exoplanet-Exomoon Survey (RLEES): GMRT Search for Electron Cyclotron Maser Emission
• Transmission spectroscopy of the ultra-hot Jupiter MASCARA-4 b: Disentangling the hydrostatic and exospheric regimes of ultra-hot Jupiters
• Three Hot-Jupiters on the upper edge of the mass-radius distribution: WASP-177, WASP-181 and WASP-183
• Combined analysis of stellar and planetary absorption lines via global forward-transit simulations
• Obliquity measurement and atmospheric characterization of the WASP-74 planetary system
• Atmospheric carbon depletion as a tracer of water oceans and biomass on temperate terrestrial exoplanets
• uGMRT observations of the hot-Saturn WASP 69b: Radio-Loud Exoplanet-Exomoon Survey II (RLEES II)
• The atmosphere of WASP-17b: Optical high-resolution transmission spectroscopy
• Aerosol Constraints on the Atmosphere of the Hot Saturn-mass planet WASP-49b
• Detection limits of exoplanetary atmospheres with 2-m class telescopes
• Characterization of exoplanetary atmospheres with SLOPpy
• Moderately misaligned orbit of the warm sub-Saturn HD 332231 b
• A Holistic and Probabilistic Approach to the Ground-based Data of HAT-P-19 System
• Probing the atmosphere of HD189733b with the Na I and K I lines
• A closer look at LTT 9779b: The ESPRESSO endeavour to pierce the atmospheric veil
• Ground-Based Transmission Spectroscopy with VLT FORS2: Evidence for faculae and clouds in the optical spectrum of the warm Saturn WASP-110b
• Extreme exomoons in WASP-49 Ab: dynamics and detectability
• Spectral signature of atmospheric winds in high resolution transit observations
• Characterization of exoplanetary atmospheres through a model-unbiased spectral survey methodology
• A Time-Resolved High-Resolution Spectroscopic Analysis of Ionized Calcium and Dynamical Processes in the Ultra-Hot Jupiter HAT-P-70 b
• Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) VIII. Nondetection of sodium in the atmosphere of the aligned planet KELT-10b
• Transmission spectroscopy of WASP-7 b with UVES -- Detection of Na I D${}_2$ and tentative D${}_1$ line absorption
• Evidence for the Late Arrival of Hot Jupiters in Systems with High Host-star Obliquities
• NuAncestor: an artificial satellite-borne star for accurate frequency calibration of ground-based EPRV spectrographs
• Investigation of the upper atmosphere in ultra-hot Jupiter WASP-76 b with high-resolution spectroscopy