327 citations · 3.1k across the 79 of their papers we have counts for
78 papers · 1 filter
WALTzER: Wide-band Atmospheric Laboratory for Transiting Exoplanet Research
A. G. Sreejith, L. Fossati, M. Lendl +81
Understanding the origin and evolution of planetary atmospheres, and the connection between their lower and upper atmospheric layers, remains a fundamental challenge in exoplanet s…
Ariel Tier 3 Observations: An Opportunity to Explore both Stellar and Planetary Variability through Broad Wavelength Time-domain Spectroscopy
Alexandra H. Thompson, Quentin Changeat, Theresa Luftinger +1
Ariel's Tier 3 observing strategy offers a unique opportunity to explore planetary and stellar variability in the spectral and time domain. However, without the correct toolkit, te…
Probing Exoplanetary Chemistry with Ariel: Scientific Priorities and Observational Strategies
Olivia Venot, Yamila Miguel, Robin Baeyens +30
Over the past two decades, increasingly precise observations have revealed that exoplanet atmospheres are chemically diverse and often far from equilibrium, with processes such as…
Reflation: redox-driven atmospheric inflation as tracer of super-Earth geochemistry
Lorenzo Cesario, Tim Lichtenberg, Mara Attia +3
We demonstrate that the redox-sensitivity of mantle outgassing can trigger transient episodes of atmospheric re-inflation in highly irradiated and geochemically-reduced super-Earth…
Coupling magma-ocean and atmospheres in spectral retrievals of sub-Neptunes
Yuichi Ito, Quentin Changeat
Recent high-precision atmospheric observations with JWST is enabling detailed characterization of sub-Neptune atmospheres and motivating efforts to understand and constrain their i…
A test of the Dedalus software for exoplanet atmospheric dynamics
Rick Bonhof, Quentin Changeat, James Y-K. Cho
Studying exoplanet flow and variability requires solving atmospheric dynamics equations accurately. Here we use the shallow-water equations to evaluate and employ Dedalus3, a spect…
Pre-computed aerosol extinction, scattering and asymmetry grids for scalable atmospheric retrievals
Maël M. Voyer, Quentin Changeat
The unprecedented wavelength coverage and sensitivity of the James Webb Space Telescope (JWST) permits to measure the absorption features of a wide range of condensate species from…
Knobs and dials of retrieving JWST transmission spectra. II. Impacts of pipeline-level differences on retrieval posteriors
Simon Schleich, Sudeshna Boro Saikia, Quentin Changeat +3
Since the launch of JWST, observations of exoplanetary atmospheres have seen a revolution in data quality. Given that atmospheric parameter inferences depend heavily on the underly…
A JWST Transit of a Jupiter Analog: II. A Search for Exomoons
David Kipping, Ben Cassese, Quentin Changeat +3
We present a search for exomoons around the Jupiter-like exoplanet Kepler-167e using a NIRSpec JWST transit. Our 60 hour time series clearly reveals the enormous impact of long-ter…
A JWST Transit of a Jupiter Analog I: Constraints on the Oblateness of Kepler-167e
Ben Cassese, David Kipping, Quentin Changeat +5
In October 2024 JWST observed a transit of Kepler-167e, a Jupiter-analog planet on a 1000+ day orbit. These observations, recorded over a long baseline of nearly 60 hours, were des…
The Atmospheric Composition of Sub-Neptune K2-18 b and Implications for its Formation
Gareb Fernández-Rodríguez, Giuseppe Morello, Jonathan C. Tan +8
Unlocking the atmospheres of sub-Neptunes is among JWST's major achievements, yet such observations demand complex analyses that strongly affect interpretations. We present an inde…
Investigating the Influence of Asymmetric Errors on Retrievals of Exoplanet Transmission Spectra
Jack J. Davey, Kai Hou Yip, Quentin Changeat +1
In studies of exoplanet atmospheres using transmission spectroscopy, Bayesian retrievals are the most popular form of analysis. In these procedures it is common to adopt a Gaussian…
Re-analysis of 10 Hot-Jupiter Atmospheres with disequilibrium chemistry retrieval
Deborah Bardet, Quentin Changeat, Olivia Venot +1
Constraining the chemical structure of exoplanetary atmospheres is pivotal for interpreting spectroscopic data and understanding planetary evolution. Traditional retrieval methods…
Cloud and Haze Parameterization in Atmospheric Retrievals: Insights from Titan's Cassini Data and JWST Observations of Hot Jupiters
Quentin Changeat, Deborah Bardet, Katy Chubb +4
Context: Before JWST, telescope observations were not sensitive enough to constrain the nature of clouds in exo-atmospheres. Recent observations, however, have inferred cloud signa…
Radiative Flux from a High-Resolution Atmospheric Dynamics Simulation of a Hot-Jupiter for JWST and Ariel
Jagat Kafle, James Y-K. Cho, Quentin Changeat
We present medium-wave (0.5~m to 13~m) radiative flux distributions and spectra derived from high-resolution atmospheric dynamics simulations of an exoplanet \WAS…
A dark, bare rock for TOI-1685 b from a JWST NIRSpec G395H phase curve
Rafael Luque, Brandon Park Coy, Qiao Xue +9
We report JWST NIRSpec/G395H observations of TOI-1685 b, a hot rocky super-Earth orbiting an M2.5V star, during a full orbit. We obtain transmission and emission spectra of the pla…
Knobs and dials of retrieving JWST transmission spectra. I. The importance of p-T profile complexity
Simon Schleich, Sudeshna Boro Saikia, Quentin Changeat +3
We investigate the impact of using multipoint p-T profiles of varying complexity on the retrieval of synthetically generated hot Jupiter transmission spectra modelled after state-o…
Reliable Detections of Atmospheres on Rocky Exoplanets with Photometric JWST Phase Curves
Mark Hammond, Claire Marie Guimond, Tim Lichtenberg +9
The prevalence of atmospheres on rocky planets is one of the major questions in exoplanet astronomy, but there are currently no published unambiguous detections of atmospheres on a…
Low abundances of TiO and VO on the Dayside of KELT-9 b: Insights from Ground-Based Photometric Observations
Yuya Hayashi, Norio Narita, Akihiko Fukui +21
We present ground-based photometric observations of secondary eclipses of the hottest known planet KELT-9b using MuSCAT2 and Sinistro. We detect secondary eclipse signals in an…
Gliese 12 b: A temperate Earth-sized planet at 12 pc ideal for atmospheric transmission spectroscopy
M. Kuzuhara, A. Fukui, J. H. Livingston +103
Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observ…
Towards atmospheric retrievals of panchromatic light-curves: ExPLOR-ing generalized inversion techniques for transiting exoplanets with JWST and Ariel
Quentin Changeat, Yuichi Ito, Ahmed F. Al-Refaie +2
Conventional atmospheric retrieval codes are designed to extract information, such as chemical abundances, thermal structures and cloud properties, from fully "reduced" spectra obt…
Measuring Tracers of Planet Formation in the Atmosphere of WASP-77A b: Sub-stellar O/H and C/H ratios, with a stellar C/O ratio and a potentially Super-stellar Ti/H ratio
Billy Edwards, Quentin Changeat
We present a comprehensive atmospheric retrieval study of the hot Jupiter WASP-77A\,b using eclipse observations from the Hubble Space Telescope (HST) and JWST. Using atmospheric r…
Is the atmosphere of the ultra-hot Jupiter WASP-121b variable?
Quentin Changeat, Jack W. Skinner, James Y-K. Cho +12
We present a comprehensive analysis of the Hubble Space Telescope observations of the atmosphere of WASP-121 b, a ultra-hot Jupiter. After reducing the transit, eclipse, and phase-…
Detecting molecules in Ariel low resolution transmission spectra
Andrea Bocchieri, Lorenzo V. Mugnai, Enzo Pascale +2
The Ariel Space Mission aims to observe a diverse sample of exoplanet atmospheres across a wide wavelength range of 0.5 to 7.8 microns. The observations are organized into four Tie…