CHEOPS finds KELT-1b darker than expected in visible light: Discrepancy between the CHEOPS and TESS eclipse depths
Artikel i vetenskaplig tidskrift, 2022
Recent studies based on photometry from the Transiting Exoplanet Survey Satellite (TESS) have suggested that the dayside of KELT-1b, a strongly irradiated brown dwarf, is significantly brighter in visible light than what would be expected based on Spitzer observations in the infrared. We observed eight eclipses of KELT-1b with CHaracterising ExOPlanet Satellite (CHEOPS) to measure its dayside brightness temperature in the bluest passband observed so far, and we jointly modelled the CHEOPS photometry with the existing optical and near-infrared photometry from TESS, LBT, CFHT, and Spitzer. Our modelling has led to a self-consistent dayside spectrum for KELT-1b covering the CHEOPS, TESS, H, Ks, and Spitzer IRAC 3.6 and 4.5 μm bands, where our TESS, H, Ks, and Spitzer band estimates largely agree with the previous studies. However, we discovered a strong discrepancy between the CHEOPS and TESS bands. The CHEOPS observations yield a higher photometric precision than the TESS observations, but they do not show a significant eclipse signal, while a deep eclipse is detected in the TESS band. The derived TESS geometric albedo of 0.36-0.13+0.12 is difficult to reconcile with a CHEOPS geometric albedo that is consistent with zero because the two passbands have considerable overlap. Variability in cloud cover caused by the transport of transient nightside clouds to the dayside could provide an explanation for reconciling the TESS and CHEOPS geometric albedos, but this hypothesis needs to be tested by future observations.
Planetary systems
Stars: individual: KELT-1
Brown dwarfs
Stars: atmospheres
Methods: observational
Författare
H. Parviainen
Instituto de Astrofísica de Canarias
Universidad de la Laguna
T.G. Wilson
University of St Andrews
M. Lendl
Université de Genève
D. Kitzmann
Universität Bern
Enric Palle
Instituto de Astrofísica de Canarias
Universidad de la Laguna
L. M. Serrano
Universita degli Studi di Torino
E. Meier Valdes
Universität Bern
W. Benz
Universität Bern
A. Deline
Université de Genève
D. Ehrenreich
Université de Genève
O. Demangeon
Universidade do Porto
A. Bonfanti
Institut fur Weltraumforschung
P. Guterman
Laboratoire d'Astrophysique de Marseille
Division Technique de I'INSU
S. Salmon
Université de Genève
Kevin Heng
The University of Warwick
Universität Bern
N. C. Santos
Universidade do Porto
S.G. Sousa
Universidade do Porto
Y. Alibert
Universität Bern
R. Alonso
Instituto de Astrofísica de Canarias
Universidad de la Laguna
Nicolas Thomas
Universität Bern
S. Udry
Université de Genève
Manfred B. Steller
Institut fur Weltraumforschung
D. Segransan
Université de Genève
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
I. Ribas
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Consejo Superior de Investigaciones Científicas (CSIC)
A.E. Simon
Universität Bern
Alexis M. S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
G.M. Szabó
Eötvös Loránd University (ELTE)
V. Van Grootel
Universite de Liège
V. Singh
Istituto nazionale di astrofisica (INAF)
D. Queloz
University of Cambridge
Eidgenössische Technische Hochschule Zürich (ETH)
N. A. Walton
University of Cambridge
Roberto Ragazzoni
Università di Padova
Istituto nazionale di astrofisica (INAF)
N. Rando
Europeiska rymdorganisationen (ESA)
Giampaolo P. Piotto
Istituto nazionale di astrofisica (INAF)
Università di Padova
P. Maxted
Keele University
M. Deleuil
Laboratoire d'Astrophysique de Marseille
G. Anglada
Centre Tecnològic de Telecomunicacions de Catalunya (CTTC)
Consejo Superior de Investigaciones Científicas (CSIC)
D. Barrado
Centro de Astrobiologia (CAB)
T. Bárczy
Admatis
W. Baumjohann
Institut fur Weltraumforschung
S.C.C. Barros
Universidade do Porto
M. Beck
Université de Genève
N. Billot
Université de Genève
T. Beck
Universität Bern
C. Broeg
Universität Bern
X. Bonfils
Domaine universitaire de Grenoble
A. Brandeker
Stockholms universitet
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Collier Cameron
University of St Andrews
S. Charnoz
Institut de Physique du Globe de Paris
H. Rauer
Technische Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Freie Universität Berlin
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
C. Corral Van Damme
Europeiska rymdorganisationen (ESA)
M. B. Davies
Lunds universitet
B.O. Demory
Universität Bern
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
L. Delrez
Universite de Liège
M. Gudel
Universität Wien
J. Farinato
Istituto nazionale di astrofisica (INAF)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
D. Gandolfi
Universita degli Studi di Torino
Michaël Gillon
Universite de Liège
L. Kiss
Eötvös Loránd University (ELTE)
Magyar Tudomanyos Akademia
S. Hoyer
Laboratoire d'Astrophysique de Marseille
K. Isaak
Europeiska rymdorganisationen (ESA)
E. Kopp
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
C. Lovis
Université de Genève
G. Peter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
D. Magrin
Istituto nazionale di astrofisica (INAF)
Don L. Pollacco
The University of Warwick
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
M. Mecina
Universität Wien
G. Olofsson
Stockholms universitet
R. Ottensamer
Universität Wien
I. Pagano
Istituto nazionale di astrofisica (INAF)
D. Piazza
Universität Bern
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 668 A93Ämneskategorier (SSIF 2011)
Meteorologi och atmosfärforskning
Astronomi, astrofysik och kosmologi
Geofysik
DOI
10.1051/0004-6361/202244117