Publications (65)
Inferring Shallow Surfaces on sub-Neptune Exoplanets with JWST
Shang-Min Tsai, Hamish Innes, Tim Lichtenberg +4
Planets smaller than Neptune and larger than Earth make up the majority of the discovered exoplanets. Those with H-rich atmospheres are prime targets for atmospheric characteri…
Near-Infrared Transmission Spectroscopy of HAT-P-18b with NIRISS: Disentangling Planetary and Stellar Features in the Era of JWST
Marylou Fournier-Tondreau, Ryan J. MacDonald, Michael Radica +24
The JWST Early Release Observations (ERO) included a NIRISS/SOSS (0.6-2.8m) transit of the 850K Saturn-mass exoplanet HAT-P-18b. Initial analysis of these dat…
Identification of carbon dioxide in an exoplanet atmosphere
The JWST Transiting Exoplanet Community Early Release Science Team, Eva-Maria Ahrer, Lili Alderson +129
Carbon dioxide (CO2) is a key chemical species that is found in a wide range of planetary atmospheres. In the context of exoplanets, CO2 is an indicator of the metal enrichment (i.…
Original Research By Young Twinkle Students (ORBYTS): Ephemeris Refinement of Transiting Exoplanets
Billy Edwards, Quentin Changeat, Kai Hou Yip +60
We report follow-up observations of transiting exoplanets that have either large uncertainties (>10 minutes) in their transit times or have not been observed for over three years.…
Awesome SOSS: Atmospheric Characterisation of WASP-96 b using the JWST Early Release Observations
Jake Taylor, Michael Radica, Luis Welbanks +13
The newly operational JWST offers the potential to study the atmospheres of distant worlds with precision that has not been achieved before. One of the first exoplanets observed by…
Photochemically-produced SO in the atmosphere of WASP-39b
Shang-Min Tsai, Elspeth K. H. Lee, Diana Powell +82
Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been…
JWST NIRISS Transmission Spectroscopy of the Super-Earth GJ 357b, a Favourable Target for Atmospheric Retention
Jake Taylor, Michael Radica, Richard D. Chatterjee +18
We present a JWST NIRISS/SOSS transmission spectrum of the super-Earth GJ 357 b: the first atmospheric observation of this exoplanet. Despite missing the first 40 % of the tr…
BOWIE-ALIGN: How formation and migration histories of giant planets impact atmospheric compositions
Anna B. T. Penzlin, Richard A. Booth, James Kirk +15
Hot Jupiters present a unique opportunity for measuring how planet formation history shapes present-day atmospheric composition. However, due to the myriad pathways influencing com…
Possible Evidence for the Presence of Volatiles on the Warm Super-Earth TOI-270 b
Louis-Philippe Coulombe, Björn Benneke, Joshua Krissansen-Totton +25
The search for atmospheres on rocky exoplanets is a crucial step in understanding the processes driving atmosphere formation, retention, and loss. Past studies have revealed the ex…
Highly reflective white clouds on the western dayside of an exo-Neptune
Louis-Philippe Coulombe, Michael Radica, Björn Benneke +19
Highly-irradiated gas giant exoplanets are predicted to show circulation patterns dominated by day-to-night heat transport and a spatial distribution of clouds that is driven by ad…
Awesome SOSS: Transmission Spectroscopy of WASP-96b with NIRISS/SOSS
Michael Radica, Luis Welbanks, Néstor Espinoza +30
The future is now - after its long-awaited launch in December 2021, JWST began science operations in July 2022 and is already revolutionizing exoplanet astronomy. The Early Release…
Quenching-driven equatorial depletion and limb asymmetries in hot Jupiter atmospheres: WASP-96b example
Maria Zamyatina, Duncan A. Christie, Eric Hébrard +11
Transport-induced quenching in hot Jupiter atmospheres is a process that determines the boundary between the part of the atmosphere at chemical equilibrium and the part of the atmo…
Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b
Taylor J. Bell, Nicolas Crouzet, Patricio E. Cubillos +80
Hot Jupiters are among the best-studied exoplanets, but it is still poorly understood how their chemical composition and cloud properties vary with longitude. Theoretical models pr…
JWST NIRSpec finds no clear signs of an atmosphere on TOI-1685 b
Chloe E. Fisher, Matthew J. Hooton, Amélie Gressier +21
Determining the prevalence of atmospheres on terrestrial planets is a core objective in exoplanetary science. While M dwarf systems offer a promising opportunity, conclusive observ…
Are there Spectral Features in the MIRI/LRS Transmission Spectrum of K2-18b?
Jake Taylor
Determining the composition of an exoplanet atmosphere relies on the presence of detectable spectral features. The strongest spectral features, including DMS, look approximately Ga…
The Hazy and Metal-Rich Atmosphere of GJ 1214 b Constrained by Near and Mid-Infrared Transmission Spectroscopy
Peter Gao, Anjali A. A. Piette, Maria E. Steinrueck +12
The near-infrared transmission spectrum of the warm sub-Neptune exoplanet GJ 1214 b has been observed to be flat and featureless, implying a high metallicity atmosphere with abunda…
Precise Constraints on the Energy Budget of WASP-121 b from its JWST NIRISS/SOSS Phase Curve
Jared Splinter, Louis-Philippe Coulombe, Robert C. Frazier +20
Ultra-hot Jupiters exhibit day-to-night temperature contrasts upwards of 1000 K due to competing effects of strong winds, short radiative timescales, magnetic drag, and H2 dissocia…
Exoplanetary Monte Carlo Radiative Transfer with Correlated-k I. Benchmarking Transit and Emission Observables
Elspeth K. H. Lee, Jake Taylor, Simon L. Grimm +4
Current observational data of exoplanets are providing increasing detail of their 3D atmospheric structures. As characterisation efforts expand in scope, the need to develop consis…
Early Release Science of the Exoplanet WASP-39b with JWST NIRSpec G395H
Lili Alderson, Hannah R. Wakeford, Munazza K. Alam +89
Measuring the abundances of carbon and oxygen in exoplanet atmospheres is considered a crucial avenue for unlocking the formation and evolution of exoplanetary systems. Access to a…
Early Release Science of the exoplanet WASP-39b with JWST NIRCam
Eva-Maria Ahrer, Kevin B. Stevenson, Megan Mansfield +96
Measuring the metallicity and carbon-to-oxygen (C/O) ratio in exoplanet atmospheres is a fundamental step towards constraining the dominant chemical processes at work and, if in eq…
The Need for Laboratory Measurements and Ab Initio Studies to Aid Understanding of Exoplanetary Atmospheres
Jonathan J. Fortney, Tyler D. Robinson, Shawn Domagal-Goldman +85
We are now on a clear trajectory for improvements in exoplanet observations that will revolutionize our ability to characterize their atmospheric structure, composition, and circul…
Strict limits on potential secondary atmospheres on the temperate rocky exo-Earth TRAPPIST-1 d
Caroline Piaulet-Ghorayeb, Björn Benneke, Martin Turbet +23
The nearby TRAPPIST-1 system, with its seven small rocky planets orbiting a late-type M8 star, offers an unprecedented opportunity to search for secondary atmospheres on temperate…
Super-Solar Metallicity and Tentative Evidence for Photochemistry on WASP-96b from JWST and Ground-Based VLT Transmission Spectroscopy
Michael Radica, Jake Taylor, Yoav Rotman +13
With its expanded wavelength coverage and increased precision compared to previous space-based observatories, JWST provides the opportunity to revisit benchmark planets and view th…
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…
No TiO detected in the hot Neptune-desert planet LTT-9779 b in reflected light at high spectral resolution
Sophia R. Vaughan, Jayne L. Birkby, Natasha E. Batalha +12
LTT-9779 b is an inhabitant of the hot Neptune desert and one of only a few planets with a measured high albedo. Characterising the atmosphere of this world is the key to understan…
Enriched volatiles and refractories but deficient titanium on the dayside atmosphere of WASP-121b revealed by JWST/NIRISS
Stefan Pelletier, Louis-Philippe Coulombe, Jared Splinter +21
With dayside temperatures elevated enough for all atmospheric constituents to be present in gas form, ultra-hot Jupiters offer a unique opportunity to probe the composition of gian…
A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve
Eliza M. -R. Kempton, Michael Zhang, Jacob L. Bean +30
There are no planets intermediate in size between Earth and Neptune in our Solar System, yet these objects are found around a substantial fraction of other stars. Population statis…
Separating flare and secondary atmospheric signals with RADYN modeling of near-infrared JWST transmission spectroscopy observations of TRAPPIST-1
Ward S. Howard, Adam F. Kowalski, Michael Radica +10
Although TRAPPIST-1's temperate planets have the highest transmission signals of any known system, flares contaminate 50-70% of transits at the 1000 ppm level, far above 100 ppm se…
Constraining the Scattered Light properties of LTT 9779 b Using HST/WFC3 UVIS
Michael Radica, Jake Taylor, Hannah R. Wakeford +5
A planet's albedo is a fundamental property that sets its energy budget by dictating the fraction of incident radiation absorbed versus reflected back to space. Generally, optical…
Diversity in the haziness and chemistry of temperate sub-Neptunes
Pierre-Alexis Roy, Björn Benneke, Marylou Fournier-Tondreau +17
Recent transit observations of K2-18b and TOI-270d revealed strong molecular absorption signatures, lending credence to the idea that temperate sub-Neptunes (T=250-40…
How Does Thermal Scattering Shape the Infrared Spectra of Cloudy Exoplanets? A Theoretical Framework and Consequences for Atmospheric Retrievals in the JWST era
Jake Taylor, Vivien Parmentier, Michael R. Line +3
Observational studies of exoplanets are suggestive of a ubiquitous presence of clouds. The current modelling techniques used in emission to account for the clouds tend to require p…
Transmission spectroscopy of WASP-52 b with JWST NIRISS: Water and helium atmospheric absorption, alongside prominent star-spot crossings
Marylou Fournier-Tondreau, Yanbo Pan, Kim Morel +20
In the era of exoplanet studies with JWST, the transiting, hot gas giant WASP-52 b provides an excellent target for atmospheric characterization through transit spectroscopy. WASP-…
BOWIE-ALIGN: Sub-stellar metallicity and carbon depletion in the aligned TrES-4b with JWST NIRSpec transmission spectroscopy
Annabella Meech, Alastair B. Claringbold, Eva-Maria Ahrer +19
The formation and migration history of a planet is expected to be imprinted in its atmosphere, in particular its carbon-to-oxygen (C/O) ratio and metallicity. The BOWIE-ALIGN progr…
A parameterised approach to disequilibrium retrievals in the JWST era: Application to NIRCam observations of HD 189733b
Jake Taylor, Shang-Min Tsai, Vivien Parmentier +2
Atmospheric retrievals are a widely used technique for inferring the physical and chemical properties of exoplanetary atmospheres from observed spectra. A common simplifying assump…
A complex structure of escaping helium spanning more than half the orbit of the ultra-hot Jupiter WASP-121\,b
Romain Allart, Louis-Philippe Coulombe, Yann Carteret +19
Atmospheric escape of planets on short orbital periods, driven by the host star's irradiation, influences their evolution, composition, and atmospheric dynamics. Our main avenue to…
Muted Features in the JWST NIRISS Transmission Spectrum of Hot-Neptune LTT 9779 b
Michael Radica, Louis-Philippe Coulombe, Jake Taylor +13
The hot-Neptune desert is one of the most sparsely populated regions of the exoplanet parameter space, and atmosphere observations of its few residents can provide insights into ho…
Simultaneous retrieval of orbital phase resolved JWST/MIRI emission spectra of the hot Jupiter WASP-43b: evidence of water, ammonia and carbon monoxide
Jingxuan Yang, Mark Hammond, Anjali A. A. Piette +14
Spectroscopic phase curves of hot Jupiters measure their emission spectra at multiple orbital phases, thus enabling detailed characterisation of their atmospheres. Precise constrai…
2.5-D retrieval of atmospheric properties from exoplanet phase curves: Application to WASP-43b observations
Patrick G. J. Irwin, Vivien Parmentier, Jake Taylor +4
We present a novel retrieval technique that attempts to model phase curve observations of exoplanets more realistically and reliably, which we call the 2.5-dimension (2.5-D) approa…
Promise and Peril: Stellar Contamination and Strict Limits on the Atmosphere Composition of TRAPPIST-1c from JWST NIRISS Transmission Spectra
Michael Radica, Caroline Piaulet-Ghorayeb, Jake Taylor +9
Attempts to probe the atmospheres of rocky planets around M dwarfs present both promise and peril. While their favorable planet-to-star radius ratios enable searches for even thin…
Continuous helium absorption from the leading and trailing tails of WASP-107b
Vigneshwaran Krishnamurthy, Yann Carteret, Caroline Piaulet-Ghorayeb +19
The detection of helium escaping the atmosphere of exoplanets has revolutionized our understanding of atmospheric escape and exoplanetary evolution. Using high-precision spectrosco…
JWST/NIRISS and HST: Exploring the improved ability to characterise exoplanet atmospheres in the JWST era
Chloe Fisher, Jake Taylor, Vivien Parmentier +6
The Hubble Space Telescope has been a pioneering instrument for studying the atmospheres of exoplanets, specifically its WFC3 and STIS instruments. With the launch of JWST, we are…
Understanding and Mitigating Biases when Studying Inhomogeneous Emission Spectra with JWST
Jake Taylor, Vivien Parmentier, Patrick G. J. Irwin +3
Exoplanet emission spectra are often modelled assuming that the hemisphere observed is well represented by a horizontally homogenised atmosphere. However this approximation will li…
A survey of exoplanet phase curves with Ariel
Benjamin Charnay, Joao M. Mendonça, Laura Kreidberg +12
The ESA-Ariel mission will include a tier dedicated to exoplanet phase curves corresponding to ~10% of the science time. We present here the current observing strategy for studying…
Horizontal transport as a source of disequilibrium chemistry on the nightside of a hot exoplanet
Vivien Parmentier, Kevin B. Stevenson, Luis Welbanks +15
Hot Jupiters have temperature gradients of several hundreds of degrees between their permanent day and nightsides. In equilibrium, the primary carbon reservoir is expected to trans…
BOWIE-ALIGN: JWST reveals hints of planetesimal accretion and complex sulphur chemistry in the atmosphere of the misaligned hot Jupiter WASP-15b
James Kirk, Eva-Maria Ahrer, Alastair B. Claringbold +23
We present a transmission spectrum of the misaligned hot Jupiter WASP-15b from 2.8-5.2 microns observed with JWST's NIRSpec/G395H grating. Our high signal to noise data, which has…
Atmospheric Reconnaissance of TRAPPIST-1 b with JWST/NIRISS: Evidence for Strong Stellar Contamination in the Transmission Spectra
Olivia Lim, Björn Benneke, René Doyon +22
TRAPPIST-1 is a nearby system of seven Earth-sized, temperate, rocky exoplanets transiting a Jupiter-sized M8.5V star, ideally suited for in-depth atmospheric studies. Each TRAPPIS…
Time Series Anomaly Detection with label-free Model Selection
Deokwoo Jung, Nandini Ramanan, Mehrnaz Amjadi +3
Anomaly detection for time-series data becomes an essential task for many data-driven applications fueled with an abundance of data and out-of-the-box machine-learning algorithms.…
Transit Timing Variations in the three-planet system: TOI-270
Laurel Kaye, Shreyas Vissapragada, Maximilian N. Gunther +69
We present ground and space-based photometric observations of TOI-270 (L231-32), a system of three transiting planets consisting of one super-Earth and two sub-Neptunes discovered…
Identifying and Fitting Eclipse Maps of Exoplanets with Cross-Validation
Mark Hammond, Neil T. Lewis, Sasha Boone +10
Eclipse mapping uses the shape of the eclipse of an exoplanet to measure its two-dimensional structure. Light curves are mostly composed of longitudinal information, with the latit…
A Moderate Albedo from Reflecting Aerosols on the Dayside of WASP-80 b Revealed by JWST/NIRISS Eclipse Spectroscopy
Kim Morel, Louis-Philippe Coulombe, Jason F. Rowe +18
Secondary eclipse observations of exoplanets at near-infrared wavelengths enable the detection of thermal emission and reflected stellar light, providing insights into the thermal…
Impact of Variable Photospheric Radius on Exoplanet Atmospheric Retrievals
Jake Taylor
Inverse techniques are used to extract information about an exoplanet's atmosphere. These techniques are prone to biased results if the appropriate forward model is not used. One a…
ARES I: WASP-76 b, A Tale of Two HST Spectra
Billy Edwards, Quentin Changeat, Robin Baeyens +25
We analyse the transmission and emission spectra of the ultra-hot Jupiter WASP-76b, observed with the G141 grism of the Hubble Space Telescope's Wide Field Camera 3 (WFC3). We redu…
Planet Hunters TESS III: two transiting planets around the bright G dwarf HD 152843
Nora L. Eisner, Belinda A. Nicholson, Oscar Barragán +37
We report on the discovery and validation of a two-planet system around a bright (V = 8.85 mag) early G dwarf (1.43 , 1.15 , TOI 2319) using data from NASA's…
The Transiting Exoplanet Community Early Release Science Program for JWST
Jacob L. Bean, Kevin B. Stevenson, Natalie M. Batalha +99
The James Webb Space Telescope (JWST) presents the opportunity to transform our understanding of planets and the origins of life by revealing the atmospheric compositions, structur…
Early Release Science of the exoplanet WASP-39b with JWST NIRISS
Adina D. Feinstein, Michael Radica, Luis Welbanks +86
Transmission spectroscopy provides insight into the atmospheric properties and consequently the formation history, physics, and chemistry of transiting exoplanets. However, obtaini…
HST PanCET Program: A Complete Near-UV to Infrared Transmission Spectrum for the Hot Jupiter WASP-79b
Alexander D. Rathcke, Ryan J. MacDonald, Joanna K. Barstow +12
We present a new optical transmission spectrum of the hot Jupiter WASP-79b. We observed three transits with the STIS instrument mounted on HST, spanning 0.3 - 1.0 um. Combining the…
BOWIE-ALIGN: A JWST comparative survey of aligned vs misaligned hot Jupiters to test the dependence of atmospheric composition on migration history
James Kirk, Eva-Maria Ahrer, Anna B. T. Penzlin +19
A primary objective of exoplanet atmosphere characterisation is to learn about planet formation and evolution, however, this is challenged by degeneracies. To determine whether dif…
Another look at the dayside spectra of WASP-43b and HD 209458b: are there scattering clouds?
Jake Taylor, Vivien Parmentier
The search for clouds on the dayside of hot Jupiters has been disadvantaged due to hot Jupiters having a limited number of high quality space-based observations. To date, retrieval…
APPLESOSS: A Producer of ProfiLEs for SOSS. Application to the NIRISS SOSS Mode
Michael Radica, Loïc Albert, Jake Taylor +12
The SOSS mode of the NIRISS instrument is poised to be one of the workhorse modes for exoplanet atmosphere observations with the newly launched James Webb Space Telescope. One of t…
Characterising a World Within the Hot Neptune Desert: Transit Observations of LTT 9779 b with HST WFC3
Billy Edwards, Quentin Changeat, Angelos Tsiaras +27
We present an atmospheric analysis of LTT 9779 b, a rare planet situated in the hot Neptune desert, that has been observed with HST WFC3 G102 and G141. The combined transmission sp…
Diurnal variations in the stratosphere of the ultrahot giant exoplanet WASP-121b
Thomas Mikal-Evans, David K. Sing, Joanna K. Barstow +9
The temperature profile of a planetary atmosphere is a key diagnostic of radiative and dynamical processes governing the absorption, redistribution, and emission of energy. Observa…
ATOCA: an algorithm to treat order contamination. Application to the NIRISS SOSS mode
Antoine Darveau-Bernier, Loïc Albert, Geert Jan Talens +20
After a successful launch, the James Webb Space Telescope is preparing to undertake one of its principal missions, the characterization of the atmospheres of exoplanets. The Single…
Sulphur dioxide in the mid-infrared transmission spectrum of WASP-39b
Diana Powell, Adina D. Feinstein, Elspeth K. H. Lee +70
The recent inference of sulphur dioxide (SO) in the atmosphere of the hot (1100 K), Saturn-mass exoplanet WASP-39b from near-infrared JWST observations suggests that phot…
SiO and a super-stellar C/O ratio in the atmosphere of the giant exoplanet WASP-121b
Thomas M. Evans-Soma, David K. Sing, Joanna K. Barstow +15
Refractory elements such as iron, magnesium, and silicon can be detected in the atmospheres of ultrahot giant planets. This provides an opportunity to quantify the amount of refrac…
Ariel: Enabling planetary science across light-years
Giovanna Tinetti, Paul Eccleston, Carole Haswell +313
Ariel, the Atmospheric Remote-sensing Infrared Exoplanet Large-survey, was adopted as the fourth medium-class mission in ESA's Cosmic Vision programme to be launched in 2029. Durin…