Spi-OPS
- Author(s)
- 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
- Abstract
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(s)
- Department of Astrophysics
- External organisation(s)
- Universität Bern, Aix-Marseille Université, Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR), University of St. Andrews, Université de Genève, Keele University, University of Cambridge, University of Warwick, Institute of Astrophysics of the Canary Islands, Geneva University Hospital, Österreichische Akademie der Wissenschaften (ÖAW), Stockholm University, Universidade do Porto, Chalmers University of Technology, INAF-Osservatorio Astrofisico di Catania, University of La Laguna, Spanish National Research Council (CSIC), Admatis Ltd., University of Grenoble Alpes, Université de Paris, Lund University, Université de Liège, Osservatorio Astronomico, Leiden University, University of Turin, European Space Agency (ESA), Hungarian Academy of Sciences, Eötvös Loránd University Budapest, The University of Sydney, Paris Observatory, Université Paris VI - Pierre-et-Marie-Curie, University of Padova, Science and Operations Department - Science Division (SCI-SC), Technische Universität Berlin, Freie Universität Berlin (FU), Ingenieurbüro Ulmer
- Journal
- Astronomy & Astrophysics
- Volume
- 658
- No. of pages
- 26
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/202141645
- Publication date
- 02-2022
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics, 103038 Space exploration
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/c432c601-3b4c-4f0c-a095-b16101ce6c1a