Spi-OPS

Autor(en)

M. J. Hooton, S. Hoyer, D. Kitzmann, B. M. Morris, A. M. S. Smith, A. Collier Cameron, D. Futyan, P. F. L. Maxted, D. Queloz, B. -O. Demory, K. Heng, M. Lendl, J. Cabrera, Sz Csizmadia, A. Deline, H. Parviainen, S. Salmon, S. Sulis, T. G. Wilson, A. Bonfanti, A. Brandeker, O. D. S. Demangeon, M. Oshagh, C. M. Persson, G. Scandariato, Y. Alibert, R. Alonso, G. Anglada Escudé, T. Bárczy, D. Barrado, S. C. C. Barros, W. Baumjohann, M. Beck, T. Beck, W. Benz, N. Billot, X. Bonfils, V. Bourrier, C. Broeg, M. -D. Busch, S. Charnoz, M. B. Davies, M. Deleuil, L. Delrez, D. Ehrenreich, A. Erikson, J. Farinato, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, M. Gillon, M. Güdel, K. G. Isaak, K. Jones, L. Kiss, J. Laskar, A. Lecavelier des Etangs, C. Lovis, A. Luntzer, D. Magrin, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, G. Piotto, D. Pollacco, R. Ragazzoni, N. Rando, F. Ratti, H. Rauer, I. Ribas, N. C. Santos, D. Ségransan, A. E. Simon, S. G. Sousa, M. Steller, Gy M. Szabó, N. Thomas, S. Udry, B. Ulmer, V. Van Grootel, N. A. Walton

Abstrakt

The light curves of tidally-locked hot Jupiters transiting fast-rotating, early type stars are a rich source of information about both planet and star, with full-phase coverage enabling a detailed atmospheric characterisation of the planet. Although it is possible to determine the true spin-orbit angle $\Psi$, a notoriously difficult parameter to measure, from any transit asymmetry resulting from gravity darkening induced by the stellar rotation, the correlations that exist between the transit parameters have led to large disagreements in published values of $\Psi$ for some systems. We aimed to study these phenomena in the light curves of the ultra-hot Jupiter MASCARA-1 b. We obtained optical CHEOPS transit and occultation light curves of MASCARA-1 b, and analysed them jointly with a Spitzer/IRAC 4.5 $\mu$m full-phase curve. When fitting the CHEOPS and Spitzer transits together, the degeneracies are greatly diminished and return results consistent with previously published Doppler tomography. Placing priors informed by the tomography achieves even better precision, allowing a determination of $\Psi=72.1^{+2.5}_{-2.4}$ deg. From the occultations and phase variations we derived dayside and nightside temperatures of $3062^{+66}_{-68}$ K and $1720\pm330$ K, respectively. In addition, we can separately derive geometric albedo $A_g=0.171^{+0.066}_{-0.068}$ and spherical albedo $A_s=0.266^{+0.097}_{-0.100}$ from the CHEOPS data, and Bond albedo $A_B=0.057^{+0.083}_{-0.101}$ from the Spitzer phase curve. Where possible, priors informed by Doppler tomography should be used when fitting transits of fast-rotating stars, though multi-colour photometry may also unlock an accurate measurement of $\Psi$. Our approach to modelling the phase variations at different wavelengths provides a template for how to separate thermal emission from reflected light in spectrally-resolved JWST phase curve data.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Universität Bern, Aix-Marseille Université, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), University of St. Andrews, Universität Genf, Keele University, University of Cambridge, University of Warwick, Instituto de Astrofísica de Canarias (IAC), Hôpitaux Universitaires de Genève, Österreichische Akademie der Wissenschaften (ÖAW), Stockholm University, Universidade do Porto, Chalmers University of Technology, INAF-Osservatorio Astrofisico di Catania, Universidad de La Laguna, Spanish National Research Council (CSIC), Admatis, Université Grenoble-Alpes, Université de Paris, Lund University, Université de Liège, INAF - Osservatorio Astronomico di Padova, Leiden University, Università degli Studi di Torino, European Space Agency (ESA), Magyar Tudományos Akadémia, Eötvös Loránd University Budapest, The University of Sydney, Observatoire de Paris, Université Paris VI - Pierre-et-Marie-Curie, Università degli Studi di Padova, European Space Research & Technology Centre (ESA/ESTEC), Technische Universität Berlin, Freie Universität Berlin (FU), Ingenieurbüro Ulmer

Journal

Astronomy & Astrophysics

Band

658

Anzahl der Seiten

26

ISSN

0004-6361

DOI

https://doi.org/10.1051/0004-6361/202141645

Publikationsdatum

02-2022

Peer-reviewed

Ja

ÖFOS 2012

103003 Astronomie, 103004 Astrophysik, 103038 Weltraumforschung

Schlagwörter

ASJC Scopus Sachgebiete

Astronomy and Astrophysics, Space and Planetary Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c432c601-3b4c-4f0c-a095-b16101ce6c1a