J/A+A/675/A167 Acoustic modes of 11 delta Scuti stars (Pamos Ortega+, 2023)
Dating young open clusters using delta Scuti stars.
Results for Trumpler 10 and Praesepe.
Pamos Ortega D., Mirouh G.M., Garcia Hernandez A., Suarez Yanes J.C.,
Barcelo-Forteza S.
<Astron. Astrophys. 675, A167 (2023)>
=2023A&A...675A.167P 2023A&A...675A.167P (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, variable ; Asteroseismology
Keywords: asteroseismology - stars: variables: delta Scuti -
open clusters and associations: general
Abstract:
The main goal of this work is to date young open clusters using delta Sct
stars. Seismic indices as the large separation and the frequency at
maximum power can help to constrain the models in order to better
characterize the stars. We propose a reliable method to identify some
radial modes, which gives us greater confidence in the constrained
models. We extract the frequency content of a sample of delta Sct stars
belonging to the same open cluster. We estimate the low-order large
separation by means of different techniques and the frequency at
maximum power for each member of the sample. We use a grid of models
built with the typical parameters of delta Sct stars, including mass,
metallicity and rotation as independent variables, in order to
determine the oscillation modes. We select the observed frequencies
whose ratios match those of the models. Once we find a range of radial
modes matching the observed frequencies, mainly the fundamental mode,
we add it to the other seismic parameters to better constrain the
stellar age. Assuming star groups have similar chemistry and age, we
estimate their mean age by computing a Weighted Probability Density
Function fit to the age distribution of the seismically constrained
models. We estimate the age of Trumpler 10 to be 30-20+30Myr, and
Praesepe, to be 580±230Myr. In this latter case, we find two
apparent populations of delta Sct stars in the same cluster, one at
510±140Myr and another at 890±140Myr. This may be due to two
different formation events, the different rotational velocities of the
members in our sample of stars, as a rapid rotation may modify the
observed large separation, or to be members of unresolved binary
systems.
Description:
We tabulate the most significant frequencies from eleven delta Scuti
stars, located in the field of the young open clusters, Trumpler 10
and Praesepe. They have been extracted using the python code
MultiModes (Pamos Ortega et al., 2022MNRAS.513..374P 2022MNRAS.513..374P)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 68 11 List of studied delta Scuti
tablea1.dat 182 1380 Most significant frequencies from
eleven delta Scuti stars
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See also:
IV/38 : TESS Input Catalog - v8.0 (TIC-8) (Stassun+, 2019)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [TIC]
5- 13 I9 --- TIC TIC number
15- 16 I2 h RAh Right ascension (J2000)
18- 19 I2 min RAm Right ascension (J2000)
21- 33 F13.10 s RAs Right ascension (J2000)
35 A1 --- DE- Declination sign (J2000)
36- 37 I2 deg DEd Declination (J2000)
39- 40 I2 arcmin DEm Declination (J2000)
42- 53 F12.9 arcsec DEs Declination (J2000)
55- 64 A10 --- Cluster Cluster (Praesepe or Trumpler10)
66- 68 I3 --- NFreq Number of frequencies in table A1
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- TIC TIC number
11- 31 F21.18 c/d Freq Frequency
33- 52 F20.18 10-3 Amp Amplitude (in ppt)
54- 75 E22.19 --- Phase Phase
77- 97 E21.17 c/d e_Freq Minimum frequency error (1)
99-119 E21.17 10-3 e_Amp Minimum amplitude error (in ppt) (1)
121-141 E21.19 --- e_Phase Minimum phase error (1)
143-162 F20.16 --- S/N Signal to noise
164-182 F19.17 --- Res Residual
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Note (1): Calculated with Montgomery et al. (1999DSSN...13...28M 1999DSSN...13...28M) method.
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Acknowledgements:
David Pamos Ortega, davidpamos(at)correo.ugr.es
(End) Patricia Vannier [CDS] 05-Jun-2023