The CHEOPS view on the climate of WASP-3 b
Abstract
Hot Jupiters are giant planets subject to intense stellar radiation. The physical and chemical properties of their atmosphere makes them the most amenable targets for the atmospheric characterization. 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. 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 which constrain the emission contribution in the \cheops and TESS passbands to approximately a few dozens of 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. WASP-3 b belongs to the group of ultra-hot Jupiters which are characterized by low Bond albedo (<0.3+-0.1), as predicted by different atmospheric models. On the other hand, it unexpectedly seems to efficiently recirculate the absorbed stellar energy, unlike similar highly irradiated planets. To explain this inconsistency, we propose that other energy recirculation mechanisms may be at play other than advection (for example, dissociation and recombination of H_2). Another possibility is that the observations in different bandpasses probe different atmospheric layers, making 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.
Keywords
Cite
@article{arxiv.2409.16268,
title = {The CHEOPS view on the climate of WASP-3 b},
author = {G. Scandariato and L. Carone and P. E. Cubillos and P. F. L. Maxted and T. Zingales and M. N. Günther and A. Heitzmann and M. Lendl and T. G. Wilson and A. Bonfanti and G. Bruno and A. Krenn and E. Meier Valdes and V. Singh and M. I. Swayne and Y. Alibert and R. Alonso and T. Bárczy and D. Barrado Navascues and S. C. C. Barros and W. Baumjohann and W. Benz and N. Billot and L. Borsato and A. Brandeker and C. Broeg and M. Buder and M. -D. Busch and A. Collier Cameron and A. C. M. Correia and Sz. Csizmadia and M. B. Davies and M. Deleuil and A. Deline and L. Delrez and O. D. S. Demangeon and B. -O. Demory and A. Derekas and B. Edwards and D. Ehrenreich and A. Erikson and J. Farinato and A. Fortier and L. Fossati and M. Fridlund and D. Gandolfi and K. Gazeas and M. Gillon and M. Güdel and Ch. Helling and K. G. Isaak and L. L. Kiss and J. Korth and K. W. F. Lam and J. Laskar and A. Lecavelier des Etangs and D. Magrin and B. Merín and C. Mordasini and V. Nascimbeni and G. Olofsson and R. Ottensamer and I. Pagano and E. Pallé and G. Peter and D. Piazza and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and N. C. Santos and D. Ségransan and A. E. Simon and A. M. S. Smith and S. G. Sousa and M. Stalport and S. Sulis and Gy. M. Szabó and S. Udry and V. Van Grootel and J. Venturini and E. Villaver and N. A. Walton},
journal= {arXiv preprint arXiv:2409.16268},
year = {2024}
}