J/A+A/679/A134 New red giants in NGC 6791 and NGC 6819 (Covelo-Paz+, 2023)
New red giants in NGC 6791 and NGC 6819 using Kepler superstamps.
Covelo-Paz A., Themessl N., Espinoza-Rojas F., Hekker S.
<Astron. Astrophys. 679, A134 (2023)>
=2023A&A...679A.134C 2023A&A...679A.134C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, giant ; Photometry ; Optical
Keywords: asteroseismology - stars: solar-type - techniques: photometric -
open clusters and associations: individual NGC 6791 -
open clusters and associations: individual NGC 6819 -
Abstract:
Stars that are members of stellar clusters are assumed to be formed at
the same time and place from material with the same initial chemical
composition. These additional constraints on the ensemble of cluster
stars make these stars suitable as benchmarks.
We aimed (1) to identify previously unknown red giants in the open
clusters NGC 6791 and NGC 6819, (2) to extract their asteroseismic
parameters and (3) to determine their cluster membership.
We followed a state-of-the-art method based on difference imaging to
extract the light curves of potential red giants in NGC 6791 and NGC
6819 from Kepler superstamp data. We extracted the asteroseismic
parameters of the stars that showed solar-like oscillations. We
performed an asteroseismic membership study to identify which of these
stars are likely to be cluster members.
We found 149 red-giant stars within the Kepler superstamps, 93 of
which are likely cluster members. We were able to find 29 red giants
that are not primary targets of Kepler, and therefore their light
curves had not been released previously. Five of these
previously-unknown red giants have a cluster membership probability
greater than 95%.
Description:
We present the light curves of the oscillating red-giant stars that we
found in the Kepler superstamps of NGC 6791 and NGC 6819.
Objects:
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RA (2000) DE Designation(s)
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19 20 53.04 +37 46 40.7 NGC 6791 = Cl Berkeley 46
19 41 18.48 +40 11 23.9 NGC 6819 = Cl Melotte 223
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File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
ngc6791.dat 94 91 NGC 6791 sources
ngc6819.dat 94 58 NGC 6819 sources
fits/* . 149 Individual fits light curves
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
Byte-by-byte Description of file: ngc6791.dat ngc6819.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number (1)
5- 12 F8.4 deg RAdeg Right ascension (J2000)
14- 20 F7.4 deg DEdeg Declination (J2000)
22- 40 I19 --- GaiaDR3 GaiaDR3 source_id
42- 48 I7 --- KIC ?=- KIC number
50- 55 F6.3 mag Gmag Gaia G magnitude
57- 61 F5.1 uHz numax Frequency at maximum power
63- 67 F5.1 uHz b_numax Lower confidence level (16%) of numax (numax_16)
69- 73 F5.1 uHz B_numax Upper confidence level (16%) of numax (numax_84)
75- 77 A3 --- Past [yes/no ] Member, this work (astero_member)
79- 81 A3 --- PS11 [yes/no ] Member, Stello et al,
2011ApJ...739...13S 2011ApJ...739...13S (S11_member)
83- 85 F3.1 --- PG20 [0/1]? Member, Cantat-Gaudin & Anters,
2020A&A...633A..99C 2020A&A...633A..99C, Cat. J/A+A/633/A99
(prob_CG20)
87- 94 A8 --- FileName Name of the fits light curve file in
subdirectory fits
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Note (1): Sources No 1-91 for NGC 6791, 92-149 for NGC 6819.
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Acknowledgements:
Alba Covelo-Paz, alba.covelopaz(at)unige.ch
(End) Patricia Vannier [CDS] 04-Oct-2023