Buchumschlag

Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission

Fuente: arXiv

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Bibliographische Detailangaben
Hauptverfasser:	Deline, A., Cubillos, P. E., Carone, L., Demory, B. -O., Lendl, M., Benz, W., Brandeker, A., Günther, M. N., Heitzmann, A., Barros, S. C. C., Kreidberg, L., Bruno, G., Kitzmann, D., Bonfanti, A., Farnir, M., Persson, C. M., Sousa, S. G., Wilson, T. G., Ehrenreich, D., Singh, V., Iro, N., Alibert, Y., Alonso, R., Bárczy, T., Navascues, D. Barrado, Baumjohann, W., Bergomi, M., Billot, N., Borsato, L., Broeg, C., Busch, M. -D., Cameron, A. Collier, Correia, A. C. M., Csizmadia, Sz., Davies, M. B., Deleuil, M., Delrez, L., Demangeon, O. D. S., Derekas, A., Edwards, B., Erikson, A., Fortier, A., Fossati, L., Fridlund, M., Gandolfi, D., Gazeas, K., Gillon, M., Güdel, M., Hasiba, J., Helling, Ch., Isaak, K. G., Kiss, L. L., Korth, J., Lam, K. W. F., Laskar, J., Étangs, A. Lecavelier des, Magrin, D., Maxted, P. F. L., Merín, B., Mordasini, C., Nascimbeni, V., Olofsson, G., Ottensamer, R., Pagano, I., Pallé, E., Peter, G., Piazza, D., Piotto, G., Pollacco, D., Queloz, D., Ragazzoni, R., Rando, N., Ratti, F., Rauer, H., Ribas, I., Santos, N. C., Scandariato, G., Ségransan, D., Simon, A. E., Smith, A. M. S., Stalport, M., Sulis, S., Szabó, Gy. M., Udry, S., Van Grootel, V., Venturini, J., Villaver, E., Walton, N. A., Westerdorff, K.
Format:	Preprint
Veröffentlicht:	2025
Schlagworte:	Earth and Planetary Astrophysics
Online-Zugang:	Acceder al recurso
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_version_	1866909689752584192
author	Deline, A. Cubillos, P. E. Carone, L. Demory, B. -O. Lendl, M. Benz, W. Brandeker, A. Günther, M. N. Heitzmann, A. Barros, S. C. C. Kreidberg, L. Bruno, G. Kitzmann, D. Bonfanti, A. Farnir, M. Persson, C. M. Sousa, S. G. Wilson, T. G. Ehrenreich, D. Singh, V. Iro, N. Alibert, Y. Alonso, R. Bárczy, T. Navascues, D. Barrado Baumjohann, W. Bergomi, M. Billot, N. Borsato, L. Broeg, C. Busch, M. -D. Cameron, A. Collier Correia, A. C. M. Csizmadia, Sz. Davies, M. B. Deleuil, M. Delrez, L. Demangeon, O. D. S. Derekas, A. Edwards, B. Erikson, A. Fortier, A. Fossati, L. Fridlund, M. Gandolfi, D. Gazeas, K. Gillon, M. Güdel, M. Hasiba, J. Helling, Ch. Isaak, K. G. Kiss, L. L. Korth, J. Lam, K. W. F. Laskar, J. Étangs, A. Lecavelier des Magrin, D. Maxted, P. F. L. Merín, B. Mordasini, C. Nascimbeni, V. Olofsson, G. Ottensamer, R. Pagano, I. Pallé, E. Peter, G. Piazza, D. Piotto, G. Pollacco, D. Queloz, D. Ragazzoni, R. Rando, N. Ratti, F. Rauer, H. Ribas, I. Santos, N. C. Scandariato, G. Ségransan, D. Simon, A. E. Smith, A. M. S. Stalport, M. Sulis, S. Szabó, Gy. M. Udry, S. Van Grootel, V. Venturini, J. Villaver, E. Walton, N. A. Westerdorff, K.
author_facet	Deline, A. Cubillos, P. E. Carone, L. Demory, B. -O. Lendl, M. Benz, W. Brandeker, A. Günther, M. N. Heitzmann, A. Barros, S. C. C. Kreidberg, L. Bruno, G. Kitzmann, D. Bonfanti, A. Farnir, M. Persson, C. M. Sousa, S. G. Wilson, T. G. Ehrenreich, D. Singh, V. Iro, N. Alibert, Y. Alonso, R. Bárczy, T. Navascues, D. Barrado Baumjohann, W. Bergomi, M. Billot, N. Borsato, L. Broeg, C. Busch, M. -D. Cameron, A. Collier Correia, A. C. M. Csizmadia, Sz. Davies, M. B. Deleuil, M. Delrez, L. Demangeon, O. D. S. Derekas, A. Edwards, B. Erikson, A. Fortier, A. Fossati, L. Fridlund, M. Gandolfi, D. Gazeas, K. Gillon, M. Güdel, M. Hasiba, J. Helling, Ch. Isaak, K. G. Kiss, L. L. Korth, J. Lam, K. W. F. Laskar, J. Étangs, A. Lecavelier des Magrin, D. Maxted, P. F. L. Merín, B. Mordasini, C. Nascimbeni, V. Olofsson, G. Ottensamer, R. Pagano, I. Pallé, E. Peter, G. Piazza, D. Piotto, G. Pollacco, D. Queloz, D. Ragazzoni, R. Rando, N. Ratti, F. Rauer, H. Ribas, I. Santos, N. C. Scandariato, G. Ségransan, D. Simon, A. E. Smith, A. M. S. Stalport, M. Sulis, S. Szabó, Gy. M. Udry, S. Van Grootel, V. Venturini, J. Villaver, E. Walton, N. A. Westerdorff, K.
contents	We performed a joint analysis of phase-curve observations of the ultra-hot Jupiter WASP-18 b from the visible to the mid-infrared, using data from CHEOPS, TESS and Spitzer. We aim to characterise the planetary atmosphere with a consistent view over the large wavelength range covered using GCMs and retrieval analyses, and including JWST data. We obtained new ephemerides with unprecedented precisions of 1 second and 1.4 millisecond on the time of inferior conjunction and orbital period, respectively. We computed a planetary radius of $R_p = 1.1926 \pm 0.0077 R_J$ with a precision of 0.65% (or 550 km). Based on a timing inconsistency with JWST, we discuss and confirm orbital eccentricity ($e = 0.00852 \pm 0.00091$). We also constrain the argument of periastron to $ω= 261.9^{+1.3}_{-1.4}$ deg. We show that the large dayside emission implies the presence of magnetic drag and super-solar metallicity. We find a steep thermally inverted gradient in the planetary atmosphere, which is common for UHJs. We detected the presence of strong CO emission lines at 4.5 $μ$m from an excess of dayside brightness in the Spitzer/IRAC/Ch2 passband. Using these models to constrain the reflected contribution in the CHEOPS passband, we derived an extremely low geometric albedo of $A_g^\text{CHEOPS} = 0.027 \pm 0.011$.
format	Preprint
id	arxiv_https___arxiv_org_abs_2505_01544
institution	arXiv
publishDate	2025
record_format	arxiv
spellingShingle	Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission Deline, A. Cubillos, P. E. Carone, L. Demory, B. -O. Lendl, M. Benz, W. Brandeker, A. Günther, M. N. Heitzmann, A. Barros, S. C. C. Kreidberg, L. Bruno, G. Kitzmann, D. Bonfanti, A. Farnir, M. Persson, C. M. Sousa, S. G. Wilson, T. G. Ehrenreich, D. Singh, V. Iro, N. Alibert, Y. Alonso, R. Bárczy, T. Navascues, D. Barrado Baumjohann, W. Bergomi, M. Billot, N. Borsato, L. Broeg, C. Busch, M. -D. Cameron, A. Collier Correia, A. C. M. Csizmadia, Sz. Davies, M. B. Deleuil, M. Delrez, L. Demangeon, O. D. S. Derekas, A. Edwards, B. Erikson, A. Fortier, A. Fossati, L. Fridlund, M. Gandolfi, D. Gazeas, K. Gillon, M. Güdel, M. Hasiba, J. Helling, Ch. Isaak, K. G. Kiss, L. L. Korth, J. Lam, K. W. F. Laskar, J. Étangs, A. Lecavelier des Magrin, D. Maxted, P. F. L. Merín, B. Mordasini, C. Nascimbeni, V. Olofsson, G. Ottensamer, R. Pagano, I. Pallé, E. Peter, G. Piazza, D. Piotto, G. Pollacco, D. Queloz, D. Ragazzoni, R. Rando, N. Ratti, F. Rauer, H. Ribas, I. Santos, N. C. Scandariato, G. Ségransan, D. Simon, A. E. Smith, A. M. S. Stalport, M. Sulis, S. Szabó, Gy. M. Udry, S. Van Grootel, V. Venturini, J. Villaver, E. Walton, N. A. Westerdorff, K. Earth and Planetary Astrophysics We performed a joint analysis of phase-curve observations of the ultra-hot Jupiter WASP-18 b from the visible to the mid-infrared, using data from CHEOPS, TESS and Spitzer. We aim to characterise the planetary atmosphere with a consistent view over the large wavelength range covered using GCMs and retrieval analyses, and including JWST data. We obtained new ephemerides with unprecedented precisions of 1 second and 1.4 millisecond on the time of inferior conjunction and orbital period, respectively. We computed a planetary radius of $R_p = 1.1926 \pm 0.0077 R_J$ with a precision of 0.65% (or 550 km). Based on a timing inconsistency with JWST, we discuss and confirm orbital eccentricity ($e = 0.00852 \pm 0.00091$). We also constrain the argument of periastron to $ω= 261.9^{+1.3}_{-1.4}$ deg. We show that the large dayside emission implies the presence of magnetic drag and super-solar metallicity. We find a steep thermally inverted gradient in the planetary atmosphere, which is common for UHJs. We detected the presence of strong CO emission lines at 4.5 $μ$m from an excess of dayside brightness in the Spitzer/IRAC/Ch2 passband. Using these models to constrain the reflected contribution in the CHEOPS passband, we derived an extremely low geometric albedo of $A_g^\text{CHEOPS} = 0.027 \pm 0.011$.
title	Dark skies of the slightly eccentric WASP-18 b from its optical-to-infrared dayside emission
topic	Earth and Planetary Astrophysics
url	https://arxiv.org/abs/2505.01544