Exoplanet atmospheres

Research group

Research theme

Sub department

About

Flow-Driven Limb-Asymmetry of Haze Distribution Part I: An Analytical Framework for Predicting the Size Distribution of Photochemical Hazes Across the Two Limbs of hot-Jupiters

Monthly Notices of the Royal Astronomical Society, Volume 550, Issue 4 (2026)

Authors:

Mei Ting Mak, Thaddeus D. Komacek, Nathan J. Mayne, David K. Sing

Abstract:

Photochemical haze, a common aerosol type expected to form in the atmospheres of hot-Jupiters, can become concentrated to different extents between the morning and evening limbs depending on the balance between advection, gravitational settling, and radiation pressure. We present a analytical framework incorporating the effect of gravity, planetary radius, and stellar flux, alongside the particle size of the haze on its resulting relative distribution between the two limbs. Using this framework and further comparing with 3D climate simulations, our framework provides a reasonable first-order estimate of the maximum radius of haze particles which would reach the morning limb and subsequently be trapped by the nightside gyres, resulting in a higher or comparable concentration of haze over the morning limb compared to the evening limb for a given hot-Jupiter atmosphere. We find that the framework performs best for higher-gravity planets, where the transport of haze particles is more strongly controlled by gravitational settling and therefore less sensitive to the approximations made in describing the atmospheric circulation. We further show that for low-gravity hot-Jupiters, even large haze particles can be readily transported to the morning limb before being removed by gravitational settling, whereas for high-gravity hot-Jupiters only small particles can survive transport to the morning limb. Our novel framework provides a rapid way to understand the transport of haze and plan limb asymmetry observations with JWST, constraining the parameter space exploration for full-scale computationally expensive 3D simulations.
More details from the publisher
Full PDF text
Details from ArXiV

Direct Imaging Discovery of Giant Exoplanet $β$ Pictoris d: A Decade-Long Game of Hide-and-Seek

(2026)

Authors:

Ben J Sutlieff, Markus J Bonse, Valentin Christiaens, Clémence Fontanive, Elisabeth C Matthews, Luke T Parker, Tim D Pearce, Jayne L Birkby, Beth A Biller, Trent J Dupuy, Emily O Garvin, Leyla Iskandarli, Jens Kammerer, Yifan Zhou, Robert J De Rosa, Aarynn L Carter, Sasha Hinkley, Matthew A Kenworthy, William O Balmer, Iain Hammond, James Mang, Caroline V Morley, Mark J Neeser, Olivier Absil, Anthony Boccaletti, Mariangela Bonavita, Brendan P Bowler, Xueqing Chen, Felix A Dannert, Julien H Girard, Markus Kasper, Anne-Marie Lagrange, Pengyu Liu, Gilles Orban de Xivry, Michael Poon, Sascha P Quanz, Benoît Serra, Johanna M Vos, Kevin Wagner, Jason Wang, Bernhard Schölkopf, Guido Agapito, Alex Agudo Berbel, Dániel Apai, Andrea Baruffolo, Martin Black, Marco Bonaglia, Runa Briguglio, Yixian Cao, Luca Carbonaro, Lee Chapman, Giovanni Cresci, Yigit Dallilar, Richard Davies, Matthias Deysenroth, Ivan Di Antonio, Amico Di Cianno, Gianluca Di Rico, David Doelman, Mauro Dolci, Frank Eisenhauer, Simone Esposito, Debora Ferruzzi, Helmut Feuchtgruber, Natascha Förster-Schreiber, Kyle Franson, Reinhard Genzel, Stefan Gillessen, Eileen C Gonzales, Michael Hartl, Jean Hayoz, Heinrich Huber, Christoph Keller, Kateryna Kravchenko, Jarron Leisenring, John Lightfoot, David Lunney, Dieter Lutz, Mike Macintosh, Filippo Mannucci, Stanimir Metchev, Thomas Ott, David Pearson, Alfio Puglisi, Sebastian Rabien, Christian Rau, Armando Riccardi, Bernardo Salasnich, Taro Shimizu, Frans Snik, Eckhard Sturm, Genaro Suárez, Linda Tacconi, Xianyu Tan, William Taylor, Christopher Waring, Marco Xompero
More details from the publisher

Magnetic field strengths of hot giant exoplanets consistent with Solar System values

(2026)

Authors:

Julia V Seidel, Vivien Parmentier, Bibiana Prinoth, Thea Hood, Nishil Mehta, Valentin De Lia, Konstantin Batygin, Tristan Guillot, Ragnar Van den Broeck, Hayley Beltz, Brian Thorsbro, Florian Debras, Daniel DB Koll, Thaddeus D Komacek, Emily Rauscher, Lorenzo Pino, Matteo Brogi, Joost P Wardenier, Jacob L Bean, Björn Benneke, Jean-Michel LB Désert, Pablo Drake, Siddharth Gandhi, Mark Hammond, David Kasper, Michael R Line, Elspeth KH Lee, Stefan Pelletier, Andreas Seifahrt, Adrien Simonnin, Peter CB Smith, Kevin B Stevenson
More details from the publisher

The Days Drag On on WASP-121 b: Interpreting Its NIRISS Spectroscopic Phase Curve with General Circulation Models

Astrophysical Journal 1004:1 (2026)

Authors:

RC Frazier, E Rauscher, J Splinter, TD Kennedy, X Tan, V Parmentier, I Malsky, LP Coulombe, R Allart, NB Cowan, D Lafrenière, R MacDonald, S Pelletier, L Dang, R Doyon, D Johnstone, L Kaltenegger, MR Meyer, C Piaulet-Ghorayeb, M Radica, JD Turner

Abstract:

Ultra-hot Jupiters (UHJs) present extreme atmospheric phenomena not found in the solar system. These planets’ daysides experience strong temperature inversions, molecular species (including H2) dissociate, and magnetism effects disrupt atmospheric circulation. On their nightsides, H2 can recombine and clouds may form. Spectroscopic phase curves allow us to measure these spatially inhomogeneous conditions, which can then be interpreted with three-dimensional (3D) models. In this work, we compare the JWST Near Infrared Imager and Slitless Spectrograph (or NIRISS) spectroscopic phase curve of the UHJ WASP-121 b to state-of-the-art 3D models with varying modeling assumptions, including the aforementioned physical phenomena. We demonstrate the importance of accurately accounting for the planet’s radius when comparing data and models, as it changes the implied overall planetary emission. We find that the 3D models predict planetary emission that is ∼12% higher than observed, contributing to the continued tension between measured and predicted hot Jupiter albedos. We identify multiple lines of evidence confirming a strong source of drag operating in this planet’s atmosphere. In addition, the nightside emission spectrum is devoid of strong absorption features, which may be best explained by nightside clouds. One feature of the dataset that is not reproduced by the 3D models is a trend toward increasingly eastward phase offsets at wavelengths shorter than ∼1.4 μm. This result is inconsistent with reflection from dayside clouds, nor can it be explained by removing atmospheric opacity sources. Our analysis highlights the complexities involved in generating 3D models and interpreting observations of UHJs in the JWST era.
More details from the publisher

The carbon isotope ratio of β Pic b with high-resolution spectroscopy

(2026)

Authors:

D González Picos, IAG Snellen, R Landman, S de Regt, N Grasser, JL Birkby, T Stolker, I Koutalios, MA Kenworthy
More details from the publisher