HR 10 as seen by CHEOPS and TESS: Revealing δ Scuti pulsations, granulation-like signal and hint for transients
Artikel i vetenskaplig tidskrift, 2024
Context. HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation explained by the binarity, but not indicative of debris-disc inhomogeneities or sublimating exocomets. On the other hand, the properties of the two stars make them potential δ Scuti pulsators. Aims. The system has been observed in two sectors by the TESS satellite, and was the target of three observing visits by CHEOPS. Thanks to these new data, we aim to further characterise the stellar properties of the two components. In particular, we aim to decipher the extent to which the photometric variability can be attributed to a stellar origin. In complement, we searched in the lightcurves for transient-type events that could reveal debris discs or exocomets. Methods. We analysed the photometric variability of both the TESS and CHEOPS datasets in detail. We first performed a frequency analysis to identify and list all the periodic signals that may be related to stellar oscillations or surface variability. The signals identified as resulting from the stellar variability were then removed from the lightcurves in order to search for transient events in the residuals. Results. We report the detection of δ Scuti pulsations in both the TESS and CHEOPS data, but we cannot definitively identify which of the components is the pulsating star. In both datasets, we find flicker noise with the characteristics of a stellar granulation signal. However, it remains difficult to firmly attribute it to actual stellar granulation from convection, given the very thin surface convective zones predicted for both stars. Finally, we report probable detection of transient events in the CHEOPS data, without clear evidence of their origin.
Sun: granulation
Techniques: photometric
Stars: variables: δ Scuti
Circumstellar matter
Stars: fundamental parameters
Författare
S. Salmon
Université de Genève
V. Van Grootel
Universite de Liège
S. Sulis
Laboratoire d'Astrophysique de Marseille
G.M. Szabó
Eötvös Loránd University (ELTE)
A. Brandeker
Stockholms universitet
C. Broeg
Universität Bern
D. Ehrenreich
Université de Genève
S. Hoyer
Laboratoire d'Astrophysique de Marseille
S.G. Sousa
Universidade do Porto
F. Kiefer
Observatoire de Paris
Institut d 'Astrophysique de Paris
D. Gandolfi
Universita degli Studi di Torino
D. Nardiello
Università di Padova
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
S. Charpinet
Institut de Recherche en Astrophysique et Planétologie (IRAP)
A. Bonfanti
Institut fur Weltraumforschung
T.G. Wilson
University of St Andrews
Y. Alibert
Universität Bern
R. Alonso
Instituto de Astrofísica de Canarias
Universidad de la Laguna
G. Anglada
Institut d'Estudis Espacials de Catalunya (IEEC)
Institut de Ciències de l'Espai (ICE) - CSIC
T. Bárczy
Admatis
D. Barrado Navascues
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
Istituto nazionale di astrofisica (INAF)
L. Borsato
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
J. Cabrera
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
V. Cessa
Universität Bern
S. Charnoz
Institut de Physique du Globe de Paris
A. Collier Cameron
University of St Andrews
C. Corral Van Damme
European Space Research and Technology Centre (ESA ESTEC)
Szilard Csizmadia
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
P. E. Cubillos
Istituto nazionale di astrofisica (INAF)
Institut fur Weltraumforschung
Melvyn B. Davies
Lunds universitet
M. Deleuil
Laboratoire d'Astrophysique de Marseille
L. Delrez
Universite de Liège
O. Demangeon
Universidade do Porto
B.O. Demory
Universität Bern
Anders Erikson
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
A. Fortier
Universität Bern
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Chalmers, Rymd-, geo- och miljövetenskap, Astronomi och plasmafysik
Universiteit Leiden
Michaël Gillon
Universite de Liège
M. Gudel
Universität Wien
J. Hasiba
Institut fur Weltraumforschung
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
L. L. Kiss
Magyar Tudomanyos Akademia
Eötvös Loránd University (ELTE)
J. Laskar
Observatoire de Paris
A. L. des Etangs
Institut d 'Astrophysique de Paris
M. Lendl
Université de Genève
C. Lovis
Université de Genève
D. Magrin
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
P. Maxted
Keele University
C. Mordasini
Universität Bern
Valerio Nascimbeni
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
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
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
Università di Padova
Don L. Pollacco
The University of Warwick
D. Queloz
Eidgenössische Technische Hochschule Zürich (ETH)
University of Cambridge
Roberto Ragazzoni
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
Università di Padova
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
Freie Universität Berlin
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Technische Universität Berlin
I. Ribas
Institut de Ciències de l'Espai (ICE) - CSIC
Institut d'Estudis Espacials de Catalunya (IEEC)
N. C. Santos
Universidade do Porto
Gaetano Scandariato
Istituto nazionale di astrofisica (INAF)
D. Segransan
Université de Genève
A.E. Simon
Universität Bern
A. M.S. Smith
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
Manfred B. Steller
Institut fur Weltraumforschung
Nicolas Thomas
Universität Bern
S. Udry
Université de Genève
J. Venturini
Université de Genève
V. Viotto
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
I. Walter
Deutsches Zentrums für Luft- und Raumfahrt (DLR)
N. A. Walton
University of Cambridge
Astronomy and Astrophysics
0004-6361 (ISSN) 1432-0746 (eISSN)
Vol. 690 A73Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1051/0004-6361/202346180