The CHEOPS view of the climate of WASP-3 b

Author(s)

G. Scandariato, L. Carone, P. E. Cubillos, P. F.L. Maxted, T. Zingales, M. N. Günther, A. Heitzmann, M. Lendl, T. G. Wilson, A. Bonfanti, G. Bruno, A. Krenn, E. Meier Valdes, V. Singh, M. I. Swayne, Y. Alibert, R. Alonso, T. Bárczy, D. Barrado Navascues, S. C.C. Barros, W. Baumjohann, W. Benz, N. Billot, L. Borsato, A. Brandeker, C. Broeg, M. Buder, M. D. Busch, A. Collier Cameron, A. C.M. Correia, Sz Csizmadia, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D.S. Demangeon, B. O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, J. Farinato, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, Ch Helling, K. G. Isaak, L. L. Kiss, J. Korth, K. W.F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, B. Merín, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, N. C. Santos, D. Ségransan, A. E. Simon, A. M.S. Smith, S. G. Sousa, M. Stalport, S. Sulis, Gy M. Szabó, S. Udry, V. Van Grootel, J. Venturini, E. Villaver, N. A. Walton

Abstract

Context. Hot Jupiters are giant planets subject to intense stellar radiation. The physical and chemical properties of their atmosphere make them the most amenable targets for atmospheric characterization. Aims. In this paper we analyze the photometry collected during the secondary eclipses of the hot Jupiter WASP-3 b by CHEOPS, TESS, and Spitzer. Our aim is to characterize the atmosphere of the planet by measuring the secondary eclipse depth in several passbands and constrain the planetary dayside spectrum. Methods. We updated the radius and the ephemeris of WASP-3 b by analyzing the transit photometry collected by CHEOPS and TESS. We also analyzed the CHEOPS, TESS, and Spitzer photometry of the occultations of the planet, measuring the eclipse depth at different wavelengths. Results. Our update of the stellar and planetary properties is consistent with previous works. The analysis of the occultations returns an eclipse depth of 92±21 ppm in the CHEOPS passband, 83±27 ppm for TESS, and >2000 ppm in the IRAC 1-2-4 Spitzer passbands. Using the eclipse depths in the Spitzer bands, we propose a set of likely emission spectra that constrain the emission contribution in the CHEOPS and TESS passbands to approximately a few dozen parts per million. This allowed us to measure a geometric albedo of 0.21±0.07 in the CHEOPS passband, while the TESS data lead to a 95% upper limit of ∼0.2. Conclusions. WASP-3 b belongs to the group of ultra-hot Jupiters that are characterized by a low Bond albedo (<0.3±0.1), as predicted by different atmospheric models. On the other hand, it seems to efficiently recirculate the absorbed stellar energy, which is not typical for similar, highly irradiated planets. To explain this inconsistency, we propose that other energy recirculation mechanisms are at play besides advection (for example, the dissociation and recombination of H₂). Another possibility is that the observations in different bandpasses probe different atmospheric layers; this would make the atmospheric analysis difficult without an appropriate modeling of the thermal emission spectrum of WASP-3 b, which is not feasible with the limited spectroscopic data available to date.

Organisation(s)

Department of Astrophysics

External organisation(s)

INAF-Osservatorio Astrofisico di Catania, Österreichische Akademie der Wissenschaften (ÖAW), INAF-Osservatorio Astrofisico di Torino, Keele University, University of Padova, Osservatorio Astronomico, Science and Operations Department - Science Division (SCI-SC), Université de Genève, University of Warwick, Universität Bern, University of Glasgow, Institute of Astrophysics of the Canary Islands, University of La Laguna, Admatis Ltd., Centro de Astrobiología (CSIC-INTA), Universidade do Porto, Stockholm University, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), University of St. Andrews, Universidade de Coimbra, Lund University, Aix-Marseille Université, Université de Liège, Katholieke Universiteit Leuven, Eötvös Loránd University Budapest, SRON Netherlands Institute for Space Research , Leiden University, Chalmers University of Technology, University of Turin, National & Kapodistrian University of Athens, Technische Universität Graz, Eötvös Loránd Research Network, Lund Observatory, Université de recherche Paris Sciences et Lettres, Université Paris VI - Pierre-et-Marie-Curie, European Space Astronomy Centre (ESA), Eidgenössische Technische Hochschule Zürich, University of Cambridge, Freie Universität Berlin (FU), Spanish National Research Council (CSIC), Institute of Space Studies of Catalonia (IEEC), HUN-REN Hungarian Research Network

Journal

Astronomy and Astrophysics

Volume

692

No. of pages

15

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202451049

Publication date

12-2024

Peer reviewed

Yes

Austrian Fields of Science 2012

103003 Astronomy, 103004 Astrophysics

Keywords

ASJC Scopus subject areas

Astronomy and Astrophysics, Space and Planetary Science

Portal url

https://ucrisportal.univie.ac.at/en/publications/fc823935-e989-4f15-906a-328b03d3fe8c