A stellar occultation by the transneptunian object (50000) Quaoar observed by CHEOPS
Journal article, 2022
Context. Stellar occultation is a powerful technique that allows the determination of some physical parameters of the occulting object. The result depends on the photometric accuracy, the temporal resolution, and the number of chords obtained. Space telescopes can achieve high photometric accuracy as they are not affected by atmospheric scintillation. Aims. Using ESA's CHEOPS space telescope, we observed a stellar occultation by the transneptunian object (50000) Quaoar. We compare the obtained chord with previous occultations by this object and determine its astrometry with sub-milliarcsecond precision. Also, we determine upper limits to the presence of a global methane atmosphere on the occulting body. Methods. We predicted and observed a stellar occultation by Quaoar using the CHEOPS space telescope. We measured the occultation light curve from this dataset and determined the dis- and reappearance of the star behind the occulting body. Furthermore, a ground-based telescope in Australia was used to constrain Quaoar's limb. Combined with results from previous works, these measurements allowed us to obtain a precise position of Quaoar at the occultation time. Results. We present the results obtained from the first stellar occultation by a transneptunian object using a space telescope orbiting Earth; it was the occultation by Quaoar observed on 2020 June 11. We used the CHEOPS light curve to obtain a surface pressure upper limit of 85 nbar for the detection of a global methane atmosphere. Also, combining this observation with a ground-based observation, we fitted Quaoar's limb to determine its astrometric position with an uncertainty below 1.0 mas. Conclusions. This observation is the first of its kind, and it shall be considered as a proof of concept of stellar occultation observations of transneptunian objects with space telescopes orbiting Earth. Moreover, it shows significant prospects for the James Webb Space Telescope.
minor planets, asteroids: individual: Quaoar
techniques: photometric
methods: observational
occultations
Author
B. E. Morgado
Federal University of Rio de Janeiro
Lab Interinst E Astron LIneA
Observatorio Nacional
G. Bruno
Istituto nazionale di astrofisica (INAF)
A. R. Gomes-Junior
Lab Interinst E Astron LIneA
São Paulo State University (UNESP)
Federal University of Uberlândia
I Pagano
Istituto nazionale di astrofisica (INAF)
B. Sicardy
Paris Descartes University
A. Fortier
University of Bern
J. Desmars
Institute of Polytechnic Science and Aeronautics (IPSA)
University of Lille
P. F. L. Maxted
Keele University
F. Braga-Ribas
Lab Interinst E Astron LIneA
Observatorio Nacional
Federal University of Technology - Paraná
D. Queloz
University of Cambridge
Swiss Federal Institute of Technology in Zürich (ETH)
S. G. Sousa
University of Porto
J. L. Ortiz
Institute of Astrophysics of Andalusia (IAA)
A. Brandeker
Stockholm University
A. Collier Cameron
University of St Andrews
C. L. Pereira
Lab Interinst E Astron LIneA
Observatorio Nacional
H. G. Floren
Stockholm University
N. Hara
University of Geneva
D. Souami
Paris Descartes University
Laboratoire Joseph-Louis Lagrange
University of Namur
K. G. Isaak
European Space Research and Technology Centre (ESA ESTEC)
G. Olofsson
Stockholm University
P. Santos-Sanz
Institute of Astrophysics of Andalusia (IAA)
T. G. Wilson
University of St Andrews
J. Broughton
Reedy Creek Observatory
Trans Tasman Occultat Alliance TTOA
Y. Alibert
University of Bern
R. Alonso
Instituto de Astrofísica de Canarias
University of La Laguna
G. Anglada
Spanish National Research Council (CSIC)
Institute of Space Studies of Catalonia (IEEC)
T. Barczy
Admatis
D. Barrado
Spanish Astrobiology Center (INTA-CSIC)
S. C. C. Barros
University of Porto
W. Baumjohann
Austrian Academy of Sciences
M. Beck
University of Geneva
T. Beck
University of Bern
W. Benz
University of Bern
N. Billot
University of Geneva
X. Bonfils
Grenoble Alpes University
C. Broeg
University of Bern
J. Cabrera
German Aerospace Center (DLR)
S. Charnoz
Paris Descartes University
S. Csizmadia
German Aerospace Center (DLR)
M. B. Davies
Lund University
M. Deleuil
Aix Marseille University
L. Delrez
University of Liège
O. D. S. Demangeon
University of Porto
B. O. Demory
University of Bern
D. Ehrenreich
University of Geneva
A. Erikson
German Aerospace Center (DLR)
L. Fossati
Austrian Academy of Sciences
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Gandolfi
University of Turin
M. Gillon
University of Liège
M. Gudel
University of Vienna
K. Heng
University of Bern
The University of Warwick
S. Hoyer
Aix Marseille University
L. L. Kiss
Eötvös Loránd University (ELTE)
Hungarian Academy of Sciences
J. Laskar
Sorbonne University
A. Lecavelier des Etangs
Sorbonne University
M. Lendl
University of Geneva
C. Lovis
University of Geneva
D. Magrin
Istituto nazionale di astrofisica (INAF)
L. Marafatto
Istituto nazionale di astrofisica (INAF)
V Nascimbeni
Istituto nazionale di astrofisica (INAF)
R. Ottensamer
University of Vienna
E. Palle
Instituto de Astrofísica de Canarias
G. Peter
German Aerospace Center (DLR)
D. Piazza
University of Bern
G. Piotto
University of Padua
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
R. Ragazzoni
Istituto nazionale di astrofisica (INAF)
University of Padua
N. Rando
European Space Agency (ESA)
F. Ratti
European Space Agency (ESA)
H. Rauer
Technische Universität Berlin
Freie Universität Berlin
German Aerospace Center (DLR)
C. Reimers
University of Vienna
I Ribas
Spanish National Research Council (CSIC)
Institute of Space Studies of Catalonia (IEEC)
N. C. Santos
University of Porto
G. Scandariato
Istituto nazionale di astrofisica (INAF)
D. Segransan
University of Geneva
A. E. Simon
University of Bern
A. M. S. Smith
German Aerospace Center (DLR)
M. Steller
Austrian Academy of Sciences
G. M. Szabo
Eötvös Loránd University (ELTE)
N. Thomas
University of Bern
S. Udry
University of Geneva
V. Van Grootel
University of Liège
N. A. Walton
University of Cambridge
K. Westerdorff
German Aerospace Center (DLR)
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 664 L15Exoplanet diversity with satellite studies
Swedish National Space Board (174/18), 2019-02-04 -- 2023-08-01.
Subject Categories
Astronomy, Astrophysics and Cosmology
Other Physics Topics
Computer Vision and Robotics (Autonomous Systems)
DOI
10.1051/0004-6361/202244221