J/AcA/72/77 Variable star population in NGC 6791 (Sanjayan+, 2022)
Variable star population in the open cluster NGC 6791 observed by the
Kepler spacecraft.
Sanjayan S., Baran A.S., Nemeth P., Kinemuchi K., Ostrowski J., Sahoo S.K.
<Acta Astron., 72, 77-102 (2022)>
=2022AcA....72...77S 2022AcA....72...77S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, variable ; Photometry ; Optical ;
Radial velocities ; Effective temperatures ; Abundances, [Fe/H]
Keywords: open clusters and associations: individual: NGC 6791 -
binaries: general - stars: oscillations - stars: rotation
Abstract:
We present the list of variable stars we found in the Kepler
superstamp data covering approximately 9' from the central region of
NGC6791. We classified the variable stars based on the variability
type and we established their cluster membership based on the
available Gaia Early Data Release 3 astrometry, by means of the
Bayesian Gaussian mixture models. In total we found 278 variable
objects, among which 17 binaries, 45 pulsators, 62 rotational and five
unclassified variables are cluster members. The remaining 28 binaries,
25 pulsators, 83 rotational, four unclassified and nine unidentified
variables are either not members or their membership is not
established. In the case of eclipsing binaries we calculated the
mid-times of eclipses and derived ephemerides. We searched for eclipse
timing variation by means of the observed minus calculated diagrams.
Only three objects show significant orbital period variation.
Independently of a recently published report, we found 119 new
variables. We used isochrones calculated within the MIST project and
derived the age (8.91Gyr), average distance (4134pc) and iron
content [Fe/H] (0.26-0.28), of NGC 6791. Using the cluster members
with membership probabilities greater than 0.9, we calculated the
distance to the cluster of 4123(31) pc, which agrees with the result
from our isochrone fitting.
Description:
We presented a search for variable stars in the Kepler superstamp
data. All available pixels were searched, by means of a Fourier
amplitude spectrum, and contiguous optimal apertures for each object
that shows a significant flux variation were defined. The coordinates
of these optimal apertures werematched with optical counterparts using
Pan-STARRS. In total, we detected 278 variable stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 171 17 List of binary stars that are cluster members
table2.dat 109 45 List of cluster members showing pulsations
table3.dat 109 62 List of cluster members showing rotational
variability
table4.dat 46 5 List of cluster members with unclassified
variability
table5.dat 149 28 List of binary stars that are not cluster members
table6.dat 100 25 List of pulsators that are not cluster members
table7.dat 106 83 List of rotational variables that are not
cluster members
table8.dat 92 4 List of unclassified variables that are not
cluster members
table9.dat 43 11 List of equatorial coordinates that are
associated with superstamp pixels showing
signal in their amplitude spectra
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See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/AcA/72/267 : Variable star population in NGC 6819 (Sanjayan+, 2022)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Type [eaco] Type (G1)
3- 21 I19 --- GaiaEDR3 Gaia EDR3 identifier
22 A1 --- n_GaiaEDR3 [*] * for newly detected variables
24- 30 I7 --- KIC KIC identifier
32- 37 A6 --- n_KIC Note on KIC (G2)
40- 51 F12.9 d Porb Orbital period
53- 63 F11.9 d e_Porb ? Orbital period error
66- 78 F13.5 d T0 ?=- Time of minimum brightness (BJD)
80- 86 F7.5 d e_T0 ? Time of minimum brightness error
88- 93 F6.3 mag Gmag Gaia G magnitude
95-105 A11 --- CMD Position in the CMD (G3)
107-116 A10 --- HRD Position in the Teff, logg diagram (G3)
118-122 I5 K Teff ? Effective temperature
124-127 I4 K e_Teff ? Effective temperature error
130-134 F5.3 [cm/s2] logg ? Surface gravity
136-140 F5.3 [cm/s2] e_logg ? Surface gravity error
142-148 F7.2 km/s RV ? Radial velocity
150-154 F5.2 km/s e_RV ? Radial velocity error
157-162 F6.3 [-] [Fe/H] ? Metallicity
164-168 F5.3 [-] e_[Fe/H] ? Metallicity error
170-171 A2 -- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Type [1234] Type (G1)
3- 21 I19 --- GaiaEDR3 Gaia EDR3 identifier
22 A1 --- n_GaiaEDR3 [*] * for newly detected variables
24- 30 I7 --- KIC KIC identifier
32- 39 A8 --- n_KIC Note on KIC (G2)
40- 45 F6.3 mag Gmag Gaia G magnitude
47- 49 A3 --- CMD Position in the CMD (G3)
51- 53 A3 --- HRD Position in the Teff, logg diagram (G3)
55- 59 I5 K Teff ? Effective temperature
61- 63 I3 K e_Teff ? Effective temperature error
66- 70 F5.3 [cm/s2] logg ? Surface gravity
72- 76 F5.3 [cm/s2] e_logg ? Surface gravity error
79- 85 F7.3 km/s RV ? Radial velocity
87- 91 F5.3 km/s e_RV ? Radial velocity error
94- 99 F6.3 [-] [Fe/H] ? Metallicity
101-105 F5.3 [-] e_[Fe/H] ? Metallicity error
108-109 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 identifier
20 A1 --- n_GaiaEDR3 [*] * for newly detected variables
22- 28 I7 --- KIC ?=- KIC identifier
30- 32 A3 --- n_KIC Note on KIC (G2)
34- 38 F5.2 d Porb Orbital period
40- 45 F6.3 mag Gmag Gaia G magnitude
47- 49 A3 --- CMD Position in the CMD (G3)
51- 56 A6 --- HRD Position in the Teff, logg diagram (G3)
58- 61 I4 K Teff ? Effective temperature
63- 65 I3 K e_Teff ? Effective temperature error
68- 72 F5.3 [cm/s] logg ? Surface gravity
74- 78 F5.3 [cm/s] e_logg ? Surface gravity error
81- 87 F7.2 km/s RV ? Radial velocity
89- 92 F4.2 km/s e_RV ? Radial velocity error
94- 99 F6.3 [-] [Fe/H] ? Metallicity
101-105 F5.3 [-] e_[Fe/H] ? Metallicity error
108-109 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 identifier
21- 27 I7 --- KIC KIC identifier
29- 30 A2 --- n_KIC Note on KIC (G2)
32- 35 F4.2 d Per Period
37- 42 F6.3 mag Gmag Gaia G magnitude
44- 46 A3 --- CMD Position in the CMD (G3)
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Type [eaco] Type (G1)
3- 21 I19 --- GaiaEDR3 Gaia EDR3 identifier
22 A1 --- n_GaiaEDR3 [*i] * for newly detected variables
24- 30 I7 --- KIC ?=- KIC identifier
32- 38 A7 --- n_KIC Note on KIC (G2)
39- 51 F13.9 d Porb Orbital period
53- 63 F11.9 d e_Porb ?=- Orbital period error
66- 78 F13.5 d T0 ?=- Time of minimum brightness
80- 86 F7.5 d e_T0 ? Time of minimum brightness error
89- 94 F6.3 mag Gmag Gaia G magnitude
96- 99 I4 K Teff ? Effective temperature
101-103 I3 K e_Teff ? Effective temperature error
106-110 F5.3 [cm/s] logg ? Surface gravity
112-116 F5.3 [cm/s] e_logg ? Surface gravity error
119-124 F6.2 km/s RV ? Radial velocity
126-130 F5.2 km/s e_RV ? Radial velocity error
134-139 F6.3 [-] [Fe/H] ? Metallicity
141-145 F5.3 [-] e_[Fe/H] ? Metallicity
148-149 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Type [123456] Type (G1)
3- 21 I19 --- GaiaEDR3 Gaia EDR3 identifier
22 A1 --- n_GaiaEDR3 [*] * for newly detected variables
24- 30 I7 --- KIC KIC identifier
32- 38 A7 --- n_KIC Note on KIC (G2)
39- 44 F6.3 mag Gmag Gaia G magnitude
46- 49 I4 K Teff ? Effective temperature
51- 53 I3 K e_Teff ? Effective temperature error
56- 60 F5.3 [cm/s2] logg ? Surface gravity
62- 66 F5.3 [cm/s2] e_logg ? Surface gravity error
68- 75 F8.3 km/s RV ? Radial velocity
77- 81 F5.3 km/s e_RV ? Radial velocity error
84- 90 F7.3 [-] [Fe/H] ? Metallicity
92- 96 F5.3 [-] e_[Fe/H] ? Metallicity error
99-100 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 identifier
20 A1 --- n_GaiaEDR3 [*iI] * for newly detected variables
22- 28 I7 --- KIC ?=- KIC identifier
30- 36 A7 --- n_KIC Note on KIC (G2)
38- 43 F6.3 d Per Period
45- 50 F6.3 mag Gmag Gaia G magnitude
52- 55 I4 K Teff ? Effective temperature
57- 59 I3 K e_Teff ? Effective temperature error
62- 66 F5.3 [cm/s2] logg ? Surface gravity
68- 72 F5.3 [cm/s2] e_logg ? Surface gravity error
75- 82 F8.3 km/s RV ? Radial velocity
84- 88 F5.2 km/s e_RV ? Radial velocity error
91- 96 F6.3 [-] [Fe/H] ? Metallicity
98-102 F5.3 [-] e_[Fe/H] ? Metallicity error
105-106 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table8.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 identifier
20 A1 --- n_GaiaEDR3 [*i] * for newly detected variables
22- 28 I7 --- KIC KIC identifier
30- 31 A2 --- n_KIC Note on KIC (G2)
33- 36 F4.2 d Per Period
38- 43 F6.3 mag Gmag Gaia G magnitude
45- 48 I4 K Teff ? Effective temperature
50- 51 I2 K e_Teff ? Effective temperature error
54- 58 F5.3 [cm/s2] logg ? Surface gravity
60- 64 F5.3 [cm/s2] e_logg ? Surface gravity error
67- 72 F6.2 km/s RV ? Radial velocity
74- 77 F4.2 km/s e_RV ? Radial velocity error
80- 83 F4.2 [-] [Fe/H] ? Metallicity
85- 88 F4.2 [-] e_[Fe/H] ? Metallicity error
91- 92 A2 --- Ref Source of the spectra (G4)
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1 A1 --- New [*] * for new variable
2- 3 I2 h RAh Right ascension (J2000)
5- 6 I2 min RAm Right ascension (J2000)
8- 12 F5.2 s RAs Right ascension (J2000)
14 A1 --- DE- Declination sign (J2000)
15- 16 I2 deg DEd Declination (J2000)
18- 19 I2 arcmin DEm Declination (J2000)
21- 24 F4.1 arcsec DEs Declination (J2000)
26- 30 F5.2 d Per Period
32- 41 A10 --- Type Type
43 A1 --- Note [*] Note (1)
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Note (1): Note as follows:
* = we found no optical objects that could be a source of the signal
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Global notes:
Note (G1): Type as follows:
e = eclipsing
a = active eclipsing
c = contact
o = outbursting
1 = gamma Dor
2 = solar-like
3 = sdBV
4 = semi-regular
5 = delta Scuti
6 = RRLyr/BLBoo
Note (G2): Note for data are available on the MAST as follows:
X = for no data,
L = for the LC data, numbers represent a total number of quarters
the date were taken in
S = for the SC data, numbers represent a total number of quarters
the date were taken in
Note (G3): Codes as follows:
MS = main sequence
RGB = red giant branch
BS = blue straggler
AGB = asymptotic giant branch
RC = red clump
HB = horizontal branch
EHB = extreme horizontal branch
The + symbol indicates that not all five astrometric parameters
were used in the membership analysis.
Note (G4): Source of the spectra as follows:
1 = HECTOSPEC (https://oirsa.cfa.harvard.edu)
2 = ESO (http://archive.eso.org)
3 = LAMOST (http://dr6.lamost.org)
4 = SDSS (http://skyserver.sdss.org/dr16)
5 = APOGEE (https://www.sdss.org/dr16/irspec)
6 = Sanjayan et al. (2022MNRAS.509..763S 2022MNRAS.509..763S)
* = indicates that the atmospheric parameters are derived
in this work
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Jun-2023