Ground-breaking exoplanet science with the ANDES spectrograph at the ELT

Experimental Astronomy Springer Nature 59:3 (2025) 29

Authors:

Enric Palle, Katia Biazzo, Emeline Bolmont, Paul Mollière, Katja Poppenhaeger, Jayne Birkby, Matteo Brogi, Gael Chauvin, Andrea Chiavassa, Jens Hoeijmakers, Emmanuel Lellouch, Christophe Lovis, Roberto Maiolino, Lisa Nortmann, Hannu Parviainen, Lorenzo Pino, Martin Turbet, Jesse Weder, Simon Albrecht, Simone Antoniucci, Susana C Barros, Andre Beaudoin, Bjorn Benneke, Isabelle Boisse, Aldo S Bonomo, Francesco Borsa, Alexis Brandeker, Wolfgang Brandner, Lars A Buchhave, Anne-Laure Cheffot, Robin Deborde, Florian Debras, Rene Doyon, Paolo Di Marcantonio, Paolo Giacobbe, Jonay I González Hernández, Ravit Helled, Laura Kreidberg, Pedro Machado, Jesus Maldonado, Alessandro Marconi, BL Canto Martins, Adriano Miceli, Christoph Mordasini, Mamadou N’Diaye, Andrzej Niedzielski, Brunella Nisini, Livia Origlia, Celine Peroux, Alexander GM Pietrow, Enrico Pinna, Emily Rauscher, Sabine Reffert, Cristina Rodríguez-López, Philippe Rousselot, Nicoletta Sanna, Nuno C Santos, Adrien Simonnin, Alejandro Suárez Mascareño, Alessio Zanutta, Maria Rosa Zapatero-Osorio, Mathias Zechmeister

Low 4.5 μm Dayside Emission Disfavors a Dark Bare-rock Scenario for the Hot Super-Earth TOI-431 b

The Astronomical Journal American Astronomical Society 169:5 (2025) 239

Authors:

Christopher Monaghan, Pierre-Alexis Roy, Björn Benneke, Ian JM Crossfield, Louis-Philippe Coulombe, Caroline Piaulet-Ghorayeb, Laura Kreidberg, Courtney D Dressing, Stephen R Kane, Diana Dragomir, Michael W Werner, Vivien Parmentier, Jessie L Christiansen, Farisa Y Morales, David Berardo, Varoujan Gorjian

A Moderate Albedo from Reflecting Aerosols on the Dayside of WASP-80 b Revealed by JWST/NIRISS Eclipse Spectroscopy

Astronomical Journal American Astronomical Society 169:5 (2025) 277

Authors:

Kim Morel, Louis-Philippe Coulombe, Jason F Rowe, David Lafrenière, Loïc Albert, Étienne Artigau, Nicolas B Cowan, Lisa Dang, Michael Radica, Jake Taylor, Caroline Piaulet-Ghorayeb, Pierre-Alexis Roy, Björn Benneke, Antoine Darveau-Bernier, Stefan Pelletier, René Doyon, Doug Johnstone, Adam B Langeveld, Romain Allart, Laura Flagg, Jake D Turner

Abstract:

Secondary eclipse observations of exoplanets at near-infrared wavelengths enable the detection of thermal emission and reflected stellar light, providing insights into the thermal structure and aerosol composition of their atmospheres. These properties are intertwined as aerosols influence the energy budget of the planet. WASP-80 b is a warm gas giant with an equilibrium temperature of 825 K orbiting a bright late-K/early-M dwarf, and for which the presence of aerosols in its atmosphere has been suggested from previous Hubble Space Telescope and Spitzer observations. We present an eclipse spectrum of WASP-80 b obtained with JWST NIRISS/SOSS, spanning 0.68–2.83 μm, which includes the first eclipse measurements below 1.1 μm for this exoplanet, extending our ability to probe light reflected by its atmosphere. When a reflected light geometric albedo is included in the atmospheric retrieval, our eclipse spectrum is best explained by a reflected light contribution of ∼30 ppm at short wavelengths, although further observations are needed to statistically confirm this preference. We measure a dayside brightness temperature of TB=811−70+69 K and constrain the reflected light geometric albedo across the SOSS wavelength range to Ag=0.204−0.056+0.051 , allowing us to estimate a 1σ range for the Bond albedo of 0.148 ≲ AB ≲ 0.383. By comparing our spectrum with aerosol models, we find that manganese sulfide and silicate clouds are disfavored, while cloud species with weak-to-moderate near-infrared reflectance, along with soots or low formation-rate tholin hazes, are consistent with our eclipse spectrum.

Are there Spectral Features in the MIRI/LRS Transmission Spectrum of K2-18b?

ArXiv 2504.15916 (2025)

The PLATO mission

Experimental Astronomy Springer 59:3 (2025) 26

Authors:

Heike Rauer, Conny Aerts, Juan Cabrera, Magali Deleuil, Anders Erikson, Laurent Gizon, Mariejo Goupil, Ana Heras, Thomas Walloschek, Jose Lorenzo-Alvarez, Filippo Marliani, César Martin-Garcia, J Miguel Mas-Hesse, Laurence O’Rourke, Hugh Osborn, Isabella Pagano, Giampaolo Piotto, Don Pollacco, Roberto Ragazzoni, Gavin Ramsay, Stéphane Udry, Thierry Appourchaux, Willy Benz, Alexis Brandeker, Suzanne Aigrain

Abstract:

PLATO (PLAnetary Transits and Oscillations of stars) is ESA’s M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large number of stars. PLATO will detect small planets (down to <2REarth) around bright stars (<11 mag), including terrestrial planets in the habitable zone of solar-like stars. With the complement of radial velocity observations from the ground, planets will be characterised for their radius, mass, and age with high accuracy (5%, 10%, 10% for an Earth-Sun combination respectively). PLATO will provide us with a large-scale catalogue of well-characterised small planets up to intermediate orbital periods, relevant for a meaningful comparison to planet formation theories and to better understand planet evolution. It will make possible comparative exoplanetology to place our Solar System planets in a broader context. In parallel, PLATO will study (host) stars using asteroseismology, allowing us to determine the stellar properties with high accuracy, substantially enhancing our knowledge of stellar structure and evolution. The payload instrument consists of 26 cameras with 12cm aperture each. For at least four years, the mission will perform high-precision photometric measurements. Here we review the science objectives, present PLATO‘s target samples and fields, provide an overview of expected core science performance as well as a description of the instrument and the mission profile towards the end of the serial production of the flight cameras. PLATO is scheduled for a launch date end 2026. This overview therefore provides a summary of the mission to the community in preparation of the upcoming operational phases.