J/A+A/673/A119 NGC 6709 cool stars rotation periods (Cole-Kodikara+, 2023)
The rotation period distribution in the young open cluster NGC 6709.
Cole-Kodikara E., Barnes S., Weingrill J., Granzer T.
<Astron. Astrophys. 673, A119 (2023)>
=2023A&A...673A.119C 2023A&A...673A.119C (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, open ; Stars, variable ; Stars, late-type ; Photometry ;
Optical
Keywords: stars: rotation - stars: solar-type - starspots -
stars: variables: general - techniques: photometric -
open clusters and associations: individual: NGC 6709
Abstract:
Open clusters serve as a useful tool for calibrating models of the
relationship between mass, rotation, and age for stars with an outer
convection zone due to the homogeneity of the stars within the
cluster. Cluster to cluster comparisons are essential to determine
whether the universality of spin-down relations holds. NGC 6709 is
chosen as a more distant representative Pleiades-age cluster for which
no rotation periods of members have previously been obtained. This
cluster is at a distance of over 1 kpc and has two red giant members.
Isochrones place the age of the cluster at around 150Myr, or
approximately the same age as the Pleiades. Photometry is obtained
over a multi-month observing season at the robotic observatory for
STELLar Activity (STELLA). After basic processing, point- spread
function photometry was derived using Daophot II, and a suite of
related software allowed us to create time series of relative
magnitude changes for each star. Four time series analysis methods are
then applied to these light curves to obtain rotation periods for
members stars. We obtain for the first time rotation periods for 45
FGK cluster members of NGC 6709. We plot the Gaia DR3 colors of the
member stars against their rotation periods and find a slow-rotating
sequence with increasing rotation periods towards redder stars and a
smaller clump of rapid rotators that have not yet joined this
sequence. NGC 6709 has rotation periods very similar to that of
another Pleiades-age open cluster, NGC 2516.
Description:
We observe NGC 6709 using STELLA to obtain multi month photometry in
the V-filter, which is then analysed using the Daophot II software
package to derive light curves for stars in the field of view with
exposure times of 24s, 120s, and 300s.
We cross-reference these stars with both the Gaia DR3 and UCAC4
catalogs and use Daophot II software to make light curves and find
periodic changs in the signal.
Objects:
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RA (2000) DE Designation(s)
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18 51 20.63 +10 20 02.4 NGC 6709 = [KPS2012] MWSC 3009
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
field.dat 243 7879 NGC 6709 field all
members.dat 107 199 NGC 6709 members
lc/* . 13717 Individual light curves
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See also:
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: field.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Gaia DR3 identifier
30- 39 A10 --- UCAC4 UCAC4 catalog identifier
41- 52 F12.8 deg RAdeg Gaia DR3 right ascension (ICRS) at Ep=2016.0
54- 64 F11.8 deg DEdeg Gaia DR3 declination (ICRS) at Ep=2016.0
66- 75 F10.7 mag Gmag Gaia DR3 G band magnitude
77- 86 F10.7 mag BPmag ? Gaia DR3 BP band magnitude
88- 97 F10.7 mag RPmag ? Gaia DR3 RP band magnitude
99-108 F10.8 mag BP-RP ? Gaia DR3 BP-RP colour index
110-121 E12.6 mas/yr pmRA Gaia DR3 proper motion right ascension
123-132 F10.8 mas/yr e_pmRA Gaia DR3 error on pmRA
134-145 F12.8 mas/yr pmDE Gaia DR3 proper motion declination
147-156 F10.8 mas/yr e_pmDE Gaia DR3 error on pmDE
158-168 E11.5 mas plx Gaia DR3 parallax
170-179 F10.8 mas e_plx Gaia DR3 error on parallax
181-186 F6.3 mag Bmag ? UCAC4 B-band magnitude
188-193 F6.3 mag Vmag ? UCAC4 V-band magnitude
195-200 F6.3 mag V24smag ? Daophot II found magnitude in 24s exposure
202-206 F5.3 mag e_V24smag ? Daophot II variability for 24s exposure
208-210 I3 --- o_V24smag ? Total number of frames star is found in
24s exposure
212-217 F6.3 mag V120smag ? Daophot II found magnitude in 120s exposure
219-223 F5.3 mag e_V120smag ? Daophot II variability for 120s exposure
225-227 I3 --- o_V120smag ? Total number of frames star is found in
120s exposure
229-234 F6.3 mag V300smag ? Daophot II found magnitude in 300s exposure
236-240 F5.3 mag e_V300smag ? Daophot II variability for 300s exposure
242-243 I2 --- o_V300smag ? Total number of frames star is found in
300s exposure
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Byte-by-byte Description of file: members.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- --- [Gaia DR3]
10- 28 I19 --- GaiaDR3 Gaia DR3 identifier
30- 39 A10 --- UCAC4 UCAC4 catalog identifier
41 A1 --- Bin? [y/n] Possibility star is a binary (1)
43- 50 F8.6 --- RUWE Gaia DR3 re-normalized unit weight error
52- 54 F3.1 --- PMemb1 ? Membership from Cantat-Gaudin et al.
(2018, Cat. J/A+A/618/A93)
56- 58 F3.1 --- PMemb2 ? Calculated membership from Gaia DR3 data
60- 64 F5.3 mag BP-RP Gaia DR3 BP-RP colour index
66- 71 F6.3 mag (BP-RP)0 Dereddened Gaia DR3 BP-RP colour index
73- 77 F5.3 mag B-V ? UCAC4 B-V colour index
79- 90 E12.6 mag (B-V)0 ? Dereddened UCAC4 B-V colour index
92- 97 F6.3 mag (B-V)calc ? Calculated (B-V)0 from (BP-RP)0 using
Appendix A in Gruner & Barnes
(2020, Cat. J/A+A/644/A16)
99-102 F4.1 d Per ? Selected period from light curve
104-107 F4.2 d e_Per ? Error of period based on FWHM of PDM
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Note (1): Based on either ruwe values > 1.4 or location above main sequence on
color-magnitude diagram using Gaia DR3 colors
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
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1- 18 F18.10 d Date Date (HJD)
20- 26 F7.4 mag mag Relative magnitude
28- 33 F6.4 mag e_mag Error on relative magnitude
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Acknowledgements:
Elizabeth Cole-Kodikara, ecolekodikara(at)aip.de
References:
Daophot II:
Stetson, 1987PASP...99..191S 1987PASP...99..191S
Stetson, P. B., Davis, L. E., & Crabtree, D. R. 1990, in Astronomical
Society of the Pacific Conference Series, Vol. 8, CCDs in astronomy,
ed. G. H. Jacoby, 289-30
(End) Patricia Vannier [CDS] 14-Mar-2023