A feature-rich transmission spectrum for WASP-127b

Abstract

WASP-127b is one of the lowest density planets discovered to date. With a sub-Saturn mass ($M_{\mathrm{p}}=0.18\pm 0.02M_J$) and super-Jupiter radius ($R_{\mathrm{p}}=1.37\pm 0.04R_J$), it orbits a bright G5 star, which is about to leave the main-sequence. We aim to explore WASP-127b's atmosphere in order to retrieve its main atmospheric components, and to find hints for its intriguing inflation and evolutionary history. We used the ALFOSC spectrograph at the NOT telescope to observe a low resolution ($R\sim 330$, seeing limited) long-slit spectroscopic time series during a planetary transit, and present here the first transmission spectrum for WASP-127b. We find the presence of a strong Rayleigh slope at blue wavelengths and a hint of Na absorption, although the quality of the data does not allow us to claim a detection. At redder wavelengths the absorption features of TiO and VO are the best explanation to fit the data. Although higher signal-to-noise ratio observations are needed to conclusively confirm the absorption features, WASP-127b seems to posses a cloud-free atmosphere and is one of the best targets to perform further characterization studies in the near future.

Accepted for Publication A&A Letters, May 22nd, 2017

References in corpus (17)

• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• Can TiO Explain Thermal Inversions in the Upper Atmospheres of Irradiated Giant Planets?
• Inflating Hot Jupiters With Ohmic Dissipation
• Towards Chemical Constraints on Hot Jupiter Migration
• Limb darkening and exoplanets: testing stellar model atmospheres and identifying biases in transit parameters
• Detection of H2O and evidence for TiO/VO in an ultra hot exoplanet atmosphere
• Exoplanetary Atmospheres - Chemistry, Formation Conditions, and Habitability
• Rayleigh scattering by H2 in the extrasolar planet HD209458b
• Exo-Transmit: An Open-Source Code for Calculating Transmission Spectra for Exoplanet Atmospheres of Varied Composition
• Probing the Blow-Off Criteria of Hydrogen-Rich "Super-Earths"
• From dense hot Jupiter to low-density Neptune: The discovery of WASP-127b, WASP-136b and WASP-138b
• Ohmic Dissipation in the Interiors of Hot Jupiters
• The GTC exoplanet transit spectroscopy survey. VII. Detection of sodium in WASP-52b's cloudy atmosphere
• The Dawes Review 3: The Atmospheres of Extrasolar Planets and Brown Dwarfs
• The GTC exoplanet transit spectroscopy survey. VI. A spectrally-resolved Rayleigh scattering slope in GJ 3470b
• The GTC exoplanet transit spectroscopy survey. IV. Confirmation of the flat transmission spectrum of HAT-P-32b
• Correcting second-order contamination in low-resolution spectra

Cited by in corpus (29)

• Detection of sodium in the atmosphere of WASP-69b
• TESS Transit Timing of Hundreds of Hot Jupiters
• The GTC exoplanet transit spectroscopy survey IX. Detection of Haze, Na, K, and Li in the super-Neptune WASP-127b
• Na I and H$\alpha$ absorption features in the atmosphere of MASCARA-2b/KELT-20b
• ExoClock Project III: 450 new exoplanet ephemerides from ground and space observations
• ARES II: Characterising the Hot Jupiters WASP-127 b, WASP-79 b and WASP-62 b with HST
• WASP-127b: A misaligned planet with a partly cloudy atmosphere and tenuous sodium signature seen by ESPRESSO
• WASP-127b transmission spectrum]{Abundance measurements of H${}_2$O and carbon-bearing species in the atmosphere of WASP-127b confirm its super-solar metallicity
• CO or no CO? Narrowing the CO abundance constraint and recovering the H2O detection in the atmosphere of WASP-127 b using SPIRou
• High-resolution transmission spectroscopy of four hot inflated gas giant exoplanets
• 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
• WASP-166b: a bloated super-Neptune transiting a V = 9 star
• The MUSCLES Extension for Atmospheric and Transmission Spectroscopy: UV and X-ray Host-star Observations for JWST ERS & GTO Targets
• LRG-BEASTS: sodium absorption and Rayleigh scattering in the atmosphere of WASP-94A b using NTT/EFOSC2
• CRIRES${}^{+}$ transmission spectroscopy of WASP-127b. Detection of the resolved signatures of a supersonic equatorial jet and cool poles in a hot planet
• The Dark World: A Tale of WASP-43b in Reflected Light with HST WFC3/UVIS
• The GTC exoplanet transit spectroscopy survey. VII. An optical transmission spectrum of WASP-48b
• Characterization of exoplanetary atmospheres with SLOPpy
• A variational model for the hyperfine resolved spectrum of VO in its ground electronic state
• Exoplanetary atmosphere target selection in the era of comparative planetology
• Ground-Based Transmission Spectroscopy with VLT FORS2: Evidence for faculae and clouds in the optical spectrum of the warm Saturn WASP-110b
• CaRM: Exploring the chromatic Rossiter-McLaughlin effect. The cases of HD 189733b and WASP-127b
• A Population Analysis of 20 Exoplanets Observed from the Optical to the Near-infrared Wavelengths with HST: Evidence for Widespread Stellar Contamination
• Probing Na in giant exoplanets with ESPRESSO and 3D NLTE stellar spectra
• An empirical spectroscopic model for eleven electronic states of VO
• DIAmante TESS AutoRegressive Planet Search (DTARPS): II. Hundreds of New TESS Candidate Exoplanets
• The GAPS programme at TNG LXVI. A homogeneous search for Na i and its possible variability in ten gas giant exoplanets
• Low-resolution Transit Spectroscopy of Three Hot Jupiters Using the 2m Himalayan Chandra Telescope