Spi-OPS: Spitzer and CHEOPS confirm the near-polar orbit of MASCARA-1 b and reveal a hint of dayside reflection
Artikel i vetenskaplig tidskrift, 2022
Context. The light curves of tidally locked hot Jupiters transiting fast-rotating, early-type stars are a rich source of information about both the 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 ψ-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 ψ for some systems. Aims. We aimed to study these phenomena in the light curves of the ultra-hot Jupiter MASCARA-1 b, which is characteristically similar to well-studied contemporaries such as KELT-9 b and WASP-33 b. Methods. We obtained optical CHaracterising ExOPlanet Satellite (CHEOPS) transit and occultation light curves of MASCARA-1 b, and analysed them jointly with a Spitzer/IRAC 4.5 μm full-phase curve to model the asymmetric transits, occultations, and phase-dependent flux modulation. For the latter, we employed a novel physics-driven approach to jointly fit the phase modulation by generating a single 2D temperature map and integrating it over the two bandpasses as a function of phase to account for the differing planet-star flux contrasts. The reflected light component was modelled using the general ab initio solution for a semi-infinite atmosphere. Results. 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 ψ = 72.1-2.4+2.5 deg. From the occultations and phase variations, we derived dayside and nightside temperatures of 3062-68+66 K and 1720 ± 330 K, respectively.Our retrieval suggests that the dayside emission spectrum closely follows that of a blackbody. As the CHEOPS occultation is too deep to be attributed to blackbody flux alone, we could separately derive geometric albedo Ag = 0.171-0.068+0.066 and spherical albedo As = 0.266-0.100+0.097 from the CHEOPS data, and Bond albedoAB = 0.057-0.101+0.083 from the Spitzer phase curve.Although small, the Ag and As indicate that MASCARA-1 b is more reflective than most other ultra-hot Jupiters, where H- absorption is expected to dominate. Conclusions. 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 ψ. 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 James Webb Space Telescope phase curve data.
Planets and satellites: atmospheres
Techniques: photometric
Planets and satellites: physical evolution
Planets and satellites: individual: MASCARA-1 b
Författare
M.J. Hooton
Universität Bern
S. Hoyer
Laboratoire d'Astrophysique de Marseille
D. Kitzmann
Universität Bern
Brett M. Morris
Universität Bern
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Collier Cameron
University of St Andrews
D. Futyan
Université de Genève
P. Maxted
Keele University
D. Queloz
University of Cambridge
Université de Genève
B.O. Demory
Universität Bern
Kevin Heng
Universität Bern
The University of Warwick
M. Lendl
Université de Genève
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Deline
Université de Genève
H. Parviainen
Instituto de Astrofísica de Canarias
S. Salmon
Université de Genève
S. Sulis
Laboratoire d'Astrophysique de Marseille
T.G. Wilson
University of St Andrews
A. Bonfanti
Institut fur Weltraumforschung
A. Brandeker
Stockholms universitet
O. Demangeon
Universidade do Porto
M. Oshagh
Instituto de Astrofísica de Canarias
Carina Persson
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
Y. Alibert
Universität Bern
R. Alonso
Instituto de Astrofísica de Canarias
Universidad de la Laguna
G. Anglada Escude´
Institut de Ciències de l'Espai (ICE) - CSIC
Institut d'Estudis Espacials de Catalunya (IEEC)
T. Bárczy
Admatis
D. Barrado
Centro de Astrobiologia (CAB)
S. C.C. Barros
Universidade do Porto
W. Baumjohann
Institut fur Weltraumforschung
M. Beck
Université de Genève
T. Beck
Universität Bern
W. Benz
Universität Bern
N. Billot
Université de Genève
X. Bonfils
Université Grenoble Alpes
V. Bourrier
Université de Genève
C. Broeg
Universität Bern
M.-D. Busch
Universität Bern
S. Charnoz
Université Paris Descartes
M. B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
L. Delrez
Universite de Liège
Université de Genève
D. Ehrenreich
Université de Genève
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Farinato
Istituto nazionale di astrofisica (INAF)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Universiteit Leiden
D. Gandolfi
Universita degli Studi di Torino
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
K. Jones
Universität Bern
L.L. Kiss
The University of Sydney
Magyar Tudomanyos Akademia
Eötvös Loránd University (ELTE)
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
C. Lovis
Université de Genève
A. Luntzer
Universität Wien
D. Magrin
Istituto nazionale di astrofisica (INAF)
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
Enric Palle
Instituto de Astrofísica de Canarias
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Giampaolo P. Piotto
Università di Padova
Istituto nazionale di astrofisica (INAF)
Don L. Pollacco
The University of Warwick
Roberto Ragazzoni
Istituto nazionale di astrofisica (INAF)
Università di Padova
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
F. Ratti
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
Technische Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Freie Universität Berlin
I. Ribas
Institut d'Estudis Espacials de Catalunya (IEEC)
Institut de Ciències de l'Espai (ICE) - CSIC
N. C. Santos
Universidade do Porto
D. Segransan
Université de Genève
A.E. Simon
Universität Bern
S. G. Sousa
Universidade do Porto
Manfred B. Steller
Institut fur Weltraumforschung
Gy M. Szabó
Eötvös Loránd University (ELTE)
Nicolas Thomas
Universität Bern
S. Udry
Université de Genève
B. Ulmer
Ingenieurbüro Ulmer - Technische Informatik
V. Van Grootel
Universite de Liège
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 658 A75Satellitstudier av exoplaneters mångfald
Rymdstyrelsen (174/18), 2019-02-04 -- 2023-08-01.
Ämneskategorier
Astronomi, astrofysik och kosmologi
Annan fysik
Den kondenserade materiens fysik
DOI
10.1051/0004-6361/202141645