Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant

K. Brogaard; F. Grundahl; E. L. Sandquist; D. Slumstrup; J. B. Thomsen; J. H. Jørgensen; J. R. Larsen; S. T. Bjørn; C. T.G. Sørensen; H. Bruntt; T. Arentoft; S. Frandsen; J. Jessen-Hansen; J. A. Orosz; R. Mathieu; A. Geller; N. Ryde; D. Stello; S. Meibom; I. Platais; Marta Lønne Jensen

doi:10.1051/0004-6361/202140911

Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant

K. Brogaard^*, F. Grundahl, E. L. Sandquist, D. Slumstrup, J. B. Thomsen, J. H. Jørgensen, J. R. Larsen, S. T. Bjørn, C. T.G. Sørensen, H. Bruntt, T. Arentoft, S. Frandsen, J. Jessen-Hansen, J. A. Orosz, R. Mathieu, A. Geller, N. Ryde, D. Stello, S. Meibom, I. PlataisMarta Lønne Jensen

^*Corresponding author for this work

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

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Abstract

Context. Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to improve the precision and accuracy of the age estimate of the host cluster. In the previous two papers of this series, we have demonstrated the use of measurements of multiple eclipsing binaries in the old open cluster NGC 6791 to set tighter constraints on the properties of stellar models than was previously possible, thereby improving both the accuracy and precision of the cluster age. Aims. We identify and measure the properties of a non-eclipsing cluster member, V56, in NGC 6791 and demonstrate how this provides additional model constraints that support and strengthen our previous findings. Methods. We analyse multi-epoch spectra of V56 from FLAMES in conjunction with the existing photometry and measurements of eclipsing binaries in NGC6971. Results. The parameters of the V56 components are found to be Mp = 1.103 ± 0.008 Mpdbl and Ms = 0.974 ± 0.007 Mpdbl, Rp = 1.764 ± 0.099 Rpdbl and Rs = 1.045 ± 0.057 Rpdbl, Teff,p = 5447 ± 125 K and Teff,s = 5552 ± 125 K, and surface [Fe/H] = +0.29 ± 0.06 assuming that they have the same abundance. Conclusions. The derived properties strengthen our previous best estimate of the cluster age of 8.3 ± 0.3 Gyr and the mass of stars on the lower red giant branch (RGB), which is MRGB = 1.15 ± 0.02 Mpdbl for NGC 6791. These numbers therefore continue to serve as verification points for other methods of age and mass measures, such as asteroseismology.

Original language	English
Article number	A178
Journal	Astronomy and Astrophysics
Volume	649
Number of pages	8
ISSN	0004-6361
DOIs	https://doi.org/10.1051/0004-6361/202140911
Publication status	Published - Jun 2021

Keywords

Binaries: spectroscopic
Open clusters and associations: individual: NGC6791
Stars: abundances
Stars: fundamental parameters
Stars: individual: V604 Lyr

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https://arxiv.org/pdf/2104.14330.pdf

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Brogaard, K., Grundahl, F., Sandquist, E. L., Slumstrup, D., Thomsen, J. B., Jørgensen, J. H., Larsen, J. R., Bjørn, S. T., Sørensen, C. T. G., Bruntt, H., Arentoft, T., Frandsen, S., Jessen-Hansen, J., Orosz, J. A., Mathieu, R., Geller, A., Ryde, N., Stello, D., Meibom, S., ... Jensen, M. L. (2021). Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant. Astronomy and Astrophysics, 649, Article A178. https://doi.org/10.1051/0004-6361/202140911

@article{e4986b0a632448bca4aba86d9233efc5,

title = "Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant",

abstract = "Context. Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to improve the precision and accuracy of the age estimate of the host cluster. In the previous two papers of this series, we have demonstrated the use of measurements of multiple eclipsing binaries in the old open cluster NGC 6791 to set tighter constraints on the properties of stellar models than was previously possible, thereby improving both the accuracy and precision of the cluster age. Aims. We identify and measure the properties of a non-eclipsing cluster member, V56, in NGC 6791 and demonstrate how this provides additional model constraints that support and strengthen our previous findings. Methods. We analyse multi-epoch spectra of V56 from FLAMES in conjunction with the existing photometry and measurements of eclipsing binaries in NGC6971. Results. The parameters of the V56 components are found to be Mp = 1.103 ± 0.008 Mpdbl and Ms = 0.974 ± 0.007 Mpdbl, Rp = 1.764 ± 0.099 Rpdbl and Rs = 1.045 ± 0.057 Rpdbl, Teff,p = 5447 ± 125 K and Teff,s = 5552 ± 125 K, and surface [Fe/H] = +0.29 ± 0.06 assuming that they have the same abundance. Conclusions. The derived properties strengthen our previous best estimate of the cluster age of 8.3 ± 0.3 Gyr and the mass of stars on the lower red giant branch (RGB), which is MRGB = 1.15 ± 0.02 Mpdbl for NGC 6791. These numbers therefore continue to serve as verification points for other methods of age and mass measures, such as asteroseismology. ",

keywords = "Binaries: spectroscopic, Open clusters and associations: individual: NGC6791, Stars: abundances, Stars: fundamental parameters, Stars: individual: V604 Lyr",

author = "K. Brogaard and F. Grundahl and Sandquist, \{E. L.\} and D. Slumstrup and Thomsen, \{J. B.\} and J{\o}rgensen, \{J. H.\} and Larsen, \{J. R.\} and Bj{\o}rn, \{S. T.\} and S{\o}rensen, \{C. T.G.\} and H. Bruntt and T. Arentoft and S. Frandsen and J. Jessen-Hansen and Orosz, \{J. A.\} and R. Mathieu and A. Geller and N. Ryde and D. Stello and S. Meibom and I. Platais and Jensen, \{Marta L{\o}nne\}",

note = "Funding Information: Acknowledgements. We thank D. A. VandenBerg for assistance in the early stages of the project and for providing the stellar models used in Fig. 6. We thank the anonymous referee for useful comments. Based on observations collected at the European Southern Observatory under ESO programme 091.D-0125(A). We gratefully acknowledge the grant from the European Social Fund via the Lithuanian Science Council (LMTLT) grant No. 09.3.3-LMT-K-712-01-0103. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. Publisher Copyright: {\textcopyright} ESO 2021.",

year = "2021",

month = jun,

doi = "10.1051/0004-6361/202140911",

language = "English",

volume = "649",

journal = "Astronomy and Astrophysics",

issn = "0004-6361",

publisher = "EDP Sciences",

}

Brogaard, K , Grundahl, F, Sandquist, EL, Slumstrup, D, Thomsen, JB, Jørgensen, JH, Larsen, JR, Bjørn, ST, Sørensen, CTG, Bruntt, H, Arentoft, T, Frandsen, S , Jessen-Hansen, J, Orosz, JA, Mathieu, R, Geller, A, Ryde, N, Stello, D, Meibom, S, Platais, I & Jensen, ML 2021, 'Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant', Astronomy and Astrophysics, vol. 649, A178. https://doi.org/10.1051/0004-6361/202140911

Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant. / Brogaard, K.; Grundahl, F.; Sandquist, E. L. et al.
In: Astronomy and Astrophysics, Vol. 649, A178, 06.2021.

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaper › Journal article › Research › peer-review

TY - JOUR

T1 - Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members

T2 - III. Constraints from a subgiant

AU - Brogaard, K.

AU - Grundahl, F.

AU - Sandquist, E. L.

AU - Slumstrup, D.

AU - Thomsen, J. B.

AU - Jørgensen, J. H.

AU - Larsen, J. R.

AU - Bjørn, S. T.

AU - Sørensen, C. T.G.

AU - Bruntt, H.

AU - Arentoft, T.

AU - Frandsen, S.

AU - Jessen-Hansen, J.

AU - Orosz, J. A.

AU - Mathieu, R.

AU - Geller, A.

AU - Ryde, N.

AU - Stello, D.

AU - Meibom, S.

AU - Platais, I.

AU - Jensen, Marta Lønne

N1 - Funding Information: Acknowledgements. We thank D. A. VandenBerg for assistance in the early stages of the project and for providing the stellar models used in Fig. 6. We thank the anonymous referee for useful comments. Based on observations collected at the European Southern Observatory under ESO programme 091.D-0125(A). We gratefully acknowledge the grant from the European Social Fund via the Lithuanian Science Council (LMTLT) grant No. 09.3.3-LMT-K-712-01-0103. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (Grant agreement no.: DNRF106). This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France This paper includes data collected by the Kepler mission and obtained from the MAST data archive at the Space Telescope Science Institute (STScI). Funding for the Kepler mission is provided by the NASA Science Mission Directorate. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5–26555. Publisher Copyright: © ESO 2021.

PY - 2021/6

Y1 - 2021/6

N2 - Context. Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to improve the precision and accuracy of the age estimate of the host cluster. In the previous two papers of this series, we have demonstrated the use of measurements of multiple eclipsing binaries in the old open cluster NGC 6791 to set tighter constraints on the properties of stellar models than was previously possible, thereby improving both the accuracy and precision of the cluster age. Aims. We identify and measure the properties of a non-eclipsing cluster member, V56, in NGC 6791 and demonstrate how this provides additional model constraints that support and strengthen our previous findings. Methods. We analyse multi-epoch spectra of V56 from FLAMES in conjunction with the existing photometry and measurements of eclipsing binaries in NGC6971. Results. The parameters of the V56 components are found to be Mp = 1.103 ± 0.008 Mpdbl and Ms = 0.974 ± 0.007 Mpdbl, Rp = 1.764 ± 0.099 Rpdbl and Rs = 1.045 ± 0.057 Rpdbl, Teff,p = 5447 ± 125 K and Teff,s = 5552 ± 125 K, and surface [Fe/H] = +0.29 ± 0.06 assuming that they have the same abundance. Conclusions. The derived properties strengthen our previous best estimate of the cluster age of 8.3 ± 0.3 Gyr and the mass of stars on the lower red giant branch (RGB), which is MRGB = 1.15 ± 0.02 Mpdbl for NGC 6791. These numbers therefore continue to serve as verification points for other methods of age and mass measures, such as asteroseismology.

AB - Context. Models of stellar structure and evolution can be constrained using accurate measurements of the parameters of eclipsing binary members of open clusters. Multiple binary stars provide the means to tighten the constraints and, in turn, to improve the precision and accuracy of the age estimate of the host cluster. In the previous two papers of this series, we have demonstrated the use of measurements of multiple eclipsing binaries in the old open cluster NGC 6791 to set tighter constraints on the properties of stellar models than was previously possible, thereby improving both the accuracy and precision of the cluster age. Aims. We identify and measure the properties of a non-eclipsing cluster member, V56, in NGC 6791 and demonstrate how this provides additional model constraints that support and strengthen our previous findings. Methods. We analyse multi-epoch spectra of V56 from FLAMES in conjunction with the existing photometry and measurements of eclipsing binaries in NGC6971. Results. The parameters of the V56 components are found to be Mp = 1.103 ± 0.008 Mpdbl and Ms = 0.974 ± 0.007 Mpdbl, Rp = 1.764 ± 0.099 Rpdbl and Rs = 1.045 ± 0.057 Rpdbl, Teff,p = 5447 ± 125 K and Teff,s = 5552 ± 125 K, and surface [Fe/H] = +0.29 ± 0.06 assuming that they have the same abundance. Conclusions. The derived properties strengthen our previous best estimate of the cluster age of 8.3 ± 0.3 Gyr and the mass of stars on the lower red giant branch (RGB), which is MRGB = 1.15 ± 0.02 Mpdbl for NGC 6791. These numbers therefore continue to serve as verification points for other methods of age and mass measures, such as asteroseismology.

KW - Binaries: spectroscopic

KW - Open clusters and associations: individual: NGC6791

KW - Stars: abundances

KW - Stars: fundamental parameters

KW - Stars: individual: V604 Lyr

UR - http://www.scopus.com/inward/record.url?scp=85107424203&partnerID=8YFLogxK

U2 - 10.1051/0004-6361/202140911

DO - 10.1051/0004-6361/202140911

M3 - Journal article

AN - SCOPUS:85107424203

SN - 0004-6361

VL - 649

JO - Astronomy and Astrophysics

JF - Astronomy and Astrophysics

M1 - A178

ER -

Age and helium content of the open cluster NGC 6791 from multiple eclipsing binary members: III. Constraints from a subgiant

Abstract

Keywords

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