The EBLM Project– XI. Mass, radius, and effective temperature measurements for 23 M-dwarf companions to solar-type stars observed with CHEOPS
Journal article, 2024
Observations of low-mass stars have frequently shown a disagreement between observed stellar radii and radii predicted by theoretical stellar structure models. This ‘radius inflation’ problem could have an impact on both stellar and exoplanetary science. We present the final results of our observation programme with the CHaracterising ExOPlanet Satellite (CHEOPS) to obtain high-precision light curves of eclipsing binaries with low-mass stellar companions (EBLMs). Combined with the spectroscopic orbits of the solar-type companions, we can derive the masses, radii, and effective temperatures of 23 M-dwarf stars. We use the PYCHEOPS data analysis software to analyse their primary and secondary occultations. For all but one target, we also perform analyses with Transiting Exoplanet Survey Satellite (TESS) light curves for comparison. We have assessed the impact of starspot-induced variation on our derived parameters and account for this in our radius and effective temperature uncertainties using simulated light curves. We observe trends in inflation with both metallicity and orbital separation. We also observe a strong trend in the difference between theoretical and observational effective temperatures with metallicity. There is no such trend with orbital separation. These results are not consistent with the idea that the observed inflation in stellar radius combines with lower effective temperature to preserve the luminosity predicted by low-mass stellar models. Our EBLM systems provide high-quality and homogeneous measurements that can be used in further studies of radius inflation.
stars: fundamental parameters
stars: low-mass
binaries: eclipsing
techniques: photometric
techniques: spectroscopic
Author
M.I. Swayne
Keele University
P. Maxted
Keele University
Amaury Triaud
University of Birmingham
S. G. Sousa
University of Porto
A. Deline
University of Geneva
D. Ehrenreich
University of Geneva
S. Hoyer
Laboratoire d'Astrophysique de Marseille
G. Olofsson
Stockholm University
I. Boisse
Laboratoire d'Astrophysique de Marseille
A. Duck
Tufts University
S. Gill
The University of Warwick
D. Martin
Tufts University
J. McCormac
The University of Warwick
Carina Persson
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
A. Santerne
Laboratoire d'Astrophysique de Marseille
D. Sebastian
University of Birmingham
M.R. Standing
Open University
L. Acuña
Laboratoire d'Astrophysique de Marseille
Y. Alibert
University of Bern
R. Alonso
Instituto de Astrofísica de Canarias
G. Anglada
Institute of Space Sciences (ICE) - CSIC
T. Bárczy
Admatis
D. Barrado Navascues
European Space Astronomy Centre (ESAC)
S.C.C. Barros
University of Porto
W. Baumjohann
Institut fur Weltraumforschung
T.A. Baycroft
University of Birmingham
M. Beck
University of Geneva
T. Beck
University of Bern
W. Benz
University of Bern
N. Billot
University of Geneva
X. Bonfils
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
L. Borsato
Istituto nazionale di astrofisica (INAF)
V. Bourrier
University of Geneva
A. Brandeker
Stockholm University
C. Broeg
University of Bern
A. Carmona
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
S. Charnoz
Institut de Physique du Globe de Paris
A. Collier Cameron
University of St Andrews
Pía Cortés-Zuleta
Laboratoire d'Astrophysique de Marseille
Szilard Csizmadia
German Aerospace Center (DLR)
P. E. Cubillos
Institut fur Weltraumforschung
M. B. Davies
Lund University
M. Deleuil
Laboratoire d'Astrophysique de Marseille
X. Delfosse
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
L. Delrez
University of Liège
O. Demangeon
University of Porto
B.O. Demory
University of Bern
Georgina Dransfield
University of Birmingham
Anders Erikson
German Aerospace Center (DLR)
A. Fortier
University of Bern
T. Forveille
Institut de Planétologie et d’Astrophysique de Grenoble (IPAG)
L. Fossati
Institut fur Weltraumforschung
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
D. Gandolfi
University of Turin
Michaël Gillon
University of Liège
M. Gudel
University of Vienna
Maximilian N. Günther
European Space Research and Technology Centre (ESA ESTEC)
N.C. Hara
University of Geneva
G. Hebrard
Institut d 'Astrophysique de Paris
N. Heidari
Laboratoire d'Astrophysique de Marseille
Coel Hellier
Keele University
Ch. Helling
Institut fur Weltraumforschung
K. Isaak
European Space Research and Technology Centre (ESA ESTEC)
F. Kerschbaum
University of Vienna
F. Kiefer
Institut d 'Astrophysique de Paris
L. L. Kiss
Hungarian Academy of Sciences
V. Kunovac
The University of Warwick
S. Lalitha
University of Birmingham
K. W.F. Lam
German Aerospace Center (DLR)
J. Laskar
Paris Observatory
A. Lecavelier des Etangs
Institut d 'Astrophysique de Paris
M. Lendl
University of Geneva
D. Magrin
Istituto nazionale di astrofisica (INAF)
L. Marafatto
Istituto nazionale di astrofisica (INAF)
E. Martioli
Institut d 'Astrophysique de Paris
N.J. Miller
Polish Academy of Sciences
C. Mordasini
University of Bern
C. Moutou
Institut de Recherche en Astrophysique et Planétologie (IRAP)
Valerio Nascimbeni
Istituto nazionale di astrofisica (INAF)
R. Ottensamer
University of Vienna
I. Pagano
Istituto nazionale di astrofisica (INAF)
Enric Palle
Instituto de Astrofísica de Canarias
G. Peter
German Aerospace Center (DLR)
D. Piazza
University of Bern
Giampaolo P. Piotto
Istituto nazionale di astrofisica (INAF)
D. Pollacco
The University of Warwick
D. Queloz
Swiss Federal Institute of Technology in Zürich (ETH)
R. Ragazzoni
Istituto nazionale di astrofisica (INAF)
N. Rando
European Space Research and Technology Centre (ESA ESTEC)
H. Rauer
German Aerospace Center (DLR)
I. Ribas
Institute of Space Sciences (ICE) - CSIC
N. C. Santos
University of Porto
Gaetano 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)
R. Southworth
European Space Research and Technology Centre (ESA ESTEC)
M. Stalport
University of Liège
G.M. Szabó
Eötvös Loránd University (ELTE)
Nicolas Thomas
University of Bern
S. Udry
University of Geneva
B. Ulmer
German Aerospace Center (DLR)
V. Van Grootel
University of Liège
J. Venturini
University of Geneva
N. A. Walton
University of Cambridge
E. Willett
University of Birmingham
T.G. Wilson
University of St Andrews
Monthly Notices of the Royal Astronomical Society
00358711 (ISSN) 13652966 (eISSN)
Vol. 528 4 5703-5722Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1093/mnras/stad3866