327 citations · 2.8k across the 55 of their papers we have counts for
57 papers
JWST MEP - A World Under Spotty Starlight: Detection of CO2 and H2O in the Hot Saturn WASP-52b with JWST NIRSpec G395H
JWST GO 3969 Team, Yanbo Pan, Ryan J. MacDonald +21
Exoplanets orbiting active stars offer distinct challenges for atmospheric characterization with the JWST. Among such worlds, the hot Saturn WASP-52b (Teq 1300 K) orbits an…
Atmospheric Reconnaissance of TRAPPIST-1 f with JWST NIRISS SOSS: No Evidence for the Transit Light Source Effect
Olivia Lim, René Doyon, Ryan J. MacDonald +25
In just over three years of operation, JWST has observed all seven planets of the TRAPPIST-1 system. The two innermost planets were found to have little to no atmosphere, barring t…
The Days Drag On on WASP-121 b: Interpreting its NIRISS Spectroscopic Phase Curve with General Circulation Models
Robert C. Frazier, Emily Rauscher, Jared Splinter +18
Ultra-hot Jupiters present extreme atmospheric phenomena not found in the Solar System. These planets' daysides experience strong temperature inversions, molecular species (includi…
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…
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…
Additional JWST/NIRSpec Transits of the Rocky M Dwarf Exoplanet GJ 1132 b Reveal a Featureless Spectrum
Katherine A. Bennett, Ryan J. MacDonald, Sarah Peacock +17
As an archetypal M-dwarf rocky exoplanet, GJ 1132 b has a varied history of atmospheric measurements. At 1.13 , 1.66 , and 580 K, it orbits a bright…
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…
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…
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…
Escaping Helium and a Highly Muted Spectrum Suggest a Metal-Enriched Atmosphere on Sub-Neptune GJ3090b from JWST Transit Spectroscopy
Eva-Maria Ahrer, Michael Radica, Caroline Piaulet-Ghorayeb +27
Sub-Neptunes, the most common planet type, remain poorly understood. Their atmospheres are expected to be diverse, but their compositions are challenging to determine, even with JW…
Thermal Emission and Confirmation of the Frigid White Dwarf Exoplanet WD 1856+534b
Mary Anne Limbach, Andrew Vanderburg, Ryan J. MacDonald +12
We report the detection of thermal emission from and confirm the planetary nature of WD 1856+534b, the first transiting planet known to orbit a white dwarf star. Observations with…
Evidence for a volcanic atmosphere on the sub-Earth L98-59b
Aaron Bello-Arufe, Mario Damiano, Katherine A. Bennett +8
Assessing the prevalence of atmospheres on rocky planets around M-dwarf stars is a top priority of exoplanet science. High-energy activity from M-dwarfs can destroy the atmospheres…
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…
A Comprehensive Reanalysis of K2-18 b's JWST NIRISS+NIRSpec Transmission Spectrum
Stephen P. Schmidt, Ryan J. MacDonald, Shang-Min Tsai +13
Sub-Neptunes are the most common type of planet in our galaxy. Interior structure models suggest that the coldest sub-Neptunes could host liquid water oceans underneath their hydro…
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-…
POSEIDON: A Multidimensional Atmospheric Retrieval Code for Exoplanet Spectra
Ryan J. MacDonald
Spectroscopic observations of exoplanet atmospheres can reveal the chemical composition, temperature, cloud properties, and (potentially) the habitability of these distant worlds.…
Cthulhu: An Open Source Molecular and Atomic Cross Section Computation Code for Substellar Atmospheres
Arnav Agrawal, Ryan J. MacDonald
Atmospheric studies of exoplanets and brown dwarfs are a cutting-edge and rapidly evolving area of astrophysics research. Calculating models of exoplanet or brown dwarf spectra req…
JWST-TST DREAMS: A Super-Solar Metallicity in WASP-17 b Dayside Atmosphere from NIRISS SOSS Eclipse Spectroscopy
Amélie Gressier, Ryan J. MacDonald, Néstor Espinoza +26
We present the first emission spectrum of the hot Jupiter WASP-17 b using one eclipse observation from the JWST Near Infrared Imager and Slitless Spectrograph (NIRISS) Single Objec…
JWST-TST DREAMS: Non-Uniform Dayside Emission for WASP-17b from MIRI/LRS
Daniel Valentine, Hannah R. Wakeford, Ryan C. Challener +23
We present the first spectroscopic characterisation of the dayside atmosphere of WASP-17b in the mid-infrared using a single JWST MIRI/LRS eclipse observation. From forward-model f…
JWST/NIRISS reveals the water-rich "steam world" atmosphere of GJ 9827 d
Caroline Piaulet-Ghorayeb, Bjorn Benneke, Michael Radica +30
With sizable volatile envelopes but smaller radii than the solar system ice giants, sub-Neptunes have been revealed as one of the most common types of planet in the galaxy. While t…
An HST Transmission Spectrum of the Closest M-Dwarf Transiting Rocky Planet LTT 1445Ab
Katherine A. Bennett, David K. Sing, Kevin B. Stevenson +7
Which rocky exoplanets have atmospheres? This presumably simply question is the first that must be answered to understand the prevalence of nearby habitable planets. A mere 6.9 pc…
The MIRI Exoplanets Orbiting White Dwarfs (MEOW) Survey: Mid-Infrared Excess Reveals a Giant Planet Candidate around a Nearby White Dwarf
Mary Anne Limbach, Andrew Vanderburg, Alexander Venner +17
The MIRI Exoplanets Orbiting White dwarfs (MEOW) Survey is a cycle 2 JWST program to search for exoplanets around dozens of nearby white dwarfs via infrared excess and direct imagi…
From the Shadows: The Impact of Nightside Thermal Emission on Ultra-hot Jupiter Transmission Spectra Retrievals
John A. Kappelmeier, Ryan J. MacDonald, Nikole K. Lewis
Transmission spectroscopy is the most widely used technique for studying exoplanet atmospheres. Since the planetary nightside faces the observer during a transit, highly irradiated…
Inhomogeneous terminators on the exoplanet WASP-39 b
Néstor Espinoza, Maria E. Steinrueck, James Kirk +40
Transmission spectroscopy has been a workhorse technique over the past two decades to constrain the physical and chemical properties of exoplanet atmospheres. One of its classical…