J/ApJ/831/11 KIC 9777062 RVs & asteroseismology in NGC6811 (Sandquist+, 2016)
The age and distance of the Kepler open cluster NGC 6811 from an eclipsing
binary, turnoff star pulsation, and giant asteroseismology.
Sandquist E.L., Jessen-Hansen J., Shetrone M.D., Brogaard K., Meibom S.,
Leitner M., Stello D., Bruntt H., Antoci V., Orosz J.A., Grundahl F.,
Frandsen S.
<Astrophys. J., 831, 11-11 (2016)>
=2016ApJ...831...11S 2016ApJ...831...11S (SIMBAD/NED BibCode)
ADC_Keywords: Radial velocities ; Binaries, eclipsing ; Photometry, UBVRI ;
Stars, variable ; Cross identifications ; Clusters, open
Keywords: asteroseismology; binaries: eclipsing; binaries: spectroscopic;
open clusters and associations: individual: NGC 6811;
stars: distances; stars: variables: delta Scuti
Abstract:
We present the analysis of an eccentric, partially eclipsing
long-period (P=19.23 days) binary system KIC 9777062 that contains
main-sequence stars near the turnoff of the intermediate-age open
cluster NGC 6811. The primary is a metal-lined Am star with a possible
convective blueshift to its radial velocities, and one star (probably
the secondary) is likely to be a γ Dor pulsator. The component
masses are 1.603±0.006(stat.)±0.016(sys.) and
1.419±0.003±0.008M☉, and the radii are 1.744±0.004±0.002
and 1.544±0.002±0.002R☉. The isochrone ages of the stars are
mildly inconsistent: the age from the mass-radius combination for the
primary (1.05±0.05±0.09Gyr, where the last quote was systematic
uncertainty from models and metallicity) is smaller than that from the
secondary (1.21±0.05±0.15Gyr) and is consistent with the inference
from the color-magnitude diagram (1.00±0.05Gyr). We have improved
the measurements of the asteroseismic parameters Δν and
νmax for helium-burning stars in the cluster. The masses of the
stars appear to be larger (or alternately, the radii appear to be
smaller) than predicted from isochrones using the ages derived from
the eclipsing stars. The majority of stars near the cluster turnoff
are pulsating stars: we identify a sample of 28 δ Sct, 15
γ Dor, and 5 hybrid types. We used the period-luminosity
relation for high-amplitude δ Sct stars to fit the ensemble of
the strongest frequencies for the cluster members, finding
(m-M)V=10.37±0.03. This is larger than most previous
determinations, but smaller than values derived from the eclipsing
binary (10.47±0.05).
Description:
Long-cadence (30 minutes of exposure time) data were recorded for
KIC9777062 during the entire 17-quarter duration of the main Kepler
mission. In addition, short-cadence (1 minute of exposure time)
observations were taken during six different month-long periods within
quarters 4 (Dec 2009), 10 (June 2011), and 14 (June 2012).
In order to obtain color information for the binary, we obtained
eclipse photometry in BVIc using the Mount Laguna Observatory (MLO) 1m
telescope spanning 2012 Jun 2 to 2014 Aug 11.
Spectroscopic observations for KIC 9777062 were obtained at the
Hobby-Eberly Telescope (HET) with the High Resolution Spectrograph
(HRS) (R=60000; 4825-6750Å), the Nordic Optical Telescope (NOT)
Fibre-fed Echelle Spectrograph (FIES) (R=67000; 3700-7300Å), and
the MMT Hectoechelle (R=45000; 5150-5300Å).
To make the most effective use of the information in the CMD, we have
vetted cluster members using proper motions and radial velocities from
the literature where possible. We have attempted to use a uniform set
of photometry covering as much of the field as possible, using the
Janes+ (2013, J/AJ/145/7) data set supplemented for a few stars with
Glushkova+ (1999, J/PAZh/25/115) photometry as well as our own.
See section 4 for further explanations.
Objects:
-------------------------------------------------------------------------
RA (ICRS) DE Designation(s) (Period)
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19 37 50.59 +46 35 23.2 KIC 9777062 = TYC 3556-370-1 (P=19.230039)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 38 61 Radial velocity measurements of KIC 9777062
table4.dat 38 134 Kepler eclipse timing observations
table7.dat 123 52 Pulsating main sequence stars in the NGC 6811 field
table8.dat 105 18 Miscellaneous bright stars in the NGC 6811 field
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See also:
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
J/A+A/594/A39 : LAMOST-Kepler param. and activity indicators (Frasca+, 2016)
J/other/ApSS/355.267 : NGC 6811 CCD UBVRI photometry (Yontan+, 2015)
J/MNRAS/450/2764 : Spectroscopic survey of Kepler stars. I. (Niemczura+, 2015)
J/MNRAS/437/3473 : Temperatures of Kepler eclipsing binaries (Armstrong+, 2014)
J/A+A/564/A79 : Proper motions of open clusters from UCAC4 (Dias+, 2014)
J/ApJS/211/2 : Revised properties of Q1-16 Kepler targets (Huber+, 2014)
J/AJ/145/7 : UBVRI CCD photom. of the open cluster NGC 6811 (Janes+, 2013)
J/A+A/548/A97 : Catalogue of variable stars in open clusters (Zejda+, 2012)
J/AJ/142/160 : Kepler Mission. II. Eclipsing binaries in DR2 (Slawson+, 2011)
J/A+A/535/A3 : SuperWASP observations of pulsating Am stars (Smalley+, 2011)
J/other/RMxAA/47.309 : NGC 6811 & NGC 6830 uvby-β photometry (Pena+, 2011)
J/A+A/534/A125 : Variability of A- and F-stars from Kepler (Uytterhoeven+ 2011)
J/ApJ/733/L9 : Stellar rotation for 71 NGC 6811 members (Meibom+, 2011)
J/A+A/529/A89 : Kepler satellite variability study (Debosscher+, 2011)
J/AJ/136/118 : Open clusters as galactic disk tracers. I. (Frinchaboy+, 2008)
J/MNRAS/380/1064 : New spectroscopic orbits of Am stars (Carquillat+, 2007)
J/A+A/388/168 : Absolute proper motions of 93 open clusters (Dias+, 2002)
J/PAZh/25/115 : A study of the open cluster NGC 6811 (Glushkova+, 1999)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d BJD Modified Barycentric Julian Date, BJD-2450000
13- 18 F6.2 km/s RVela [-42/74] Radial Velocity, a
20- 23 F4.2 km/s e_RVela [0.1/1.2] Uncertainty in RVela
25- 30 F6.2 km/s RVelb [-68/65] Radial Velocity, b
32- 35 F4.2 km/s e_RVelb [0.1/2.1] Uncertainty in RVelb
38 I1 --- Inst Instrument (1)
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Note (1): Telescope/Instrument used as follows:
1 = Nordic Optical Telescope (NOT), Fibre-fed Echelle Spectrograph (FIES);
2 = Hobby-Eberly Telescope (HET), High Resolution Spectrograph (HRS);
3 = MMT, Hectoechelle.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d BJD Eclipse Timing, Modified Barycentric Julian Date;
BJD-2450000 (1)
13- 20 F8.6 d sigma [0.00001/0.0012] Residual
22 A1 --- Type [P,S] Eclipse Type ("P"rimary or "S"econdary)
24- 38 A15 --- Notes Notes (2)
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Note (1): Eclipse times were placed on Barycentric Julian Date (BJD)
barycentric dynamical time (TDB) system, with ground-based times converted
from heliocentric to barycentric time using an online tool
(http://astroutils.astronomy.ohio-state.edu/time/hjd2bjd.html,
Eastman et al. 2010PASP..122..935E 2010PASP..122..935E).
Note (2): Notes include Kepler quarter; indications of ground based data;
"SC" for short cadence Kepler data.
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Byte-by-byte Description of file: table[78].dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- S71 ? Sanders (1971A&A....15..368S 1971A&A....15..368S) identifier
5- 8 I4 --- [JBM2013] ? Janes+ (2013, J/AJ/145/7) identifier
10- 13 I4 --- Tycho ? Tycho identifier, TYC 3556-XXXXX-1
15- 21 I7 --- KIC Kepler Input Catalog identifier
23- 24 I2 h RAh [19] Hour of Right Ascension (J2000)
26- 27 I2 min RAm [35/39] Minute of Right Ascension (J2000)
29- 33 F5.2 s RAs Second of Right Ascension (J2000)
35- 35 A1 --- DE- [+] Sign of the Declination (J2000)
36- 37 I2 deg DEd [45/46] Degree of Declination (J2000)
39- 40 I2 arcmin DEm Arcminute of Declination (J2000)
42- 45 F4.1 arcsec DEs Arcsecond of Declination (J2000)
47- 52 F6.3 mag Vmag [10.8/15.5] V band magnitude;
Mount Laguna Observatory 1m
54- 58 F5.3 mag e_Vmag [0.001/0.08]? Uncertainty in Vmag
60- 64 F5.3 mag B-V [0.1/1] B-V color index;
Mount Laguna Observatory 1m
66- 70 F5.3 mag e_B-V [0.001/0.08]? Uncertainty in B-V
72- 76 F5.3 mag V-Ic [0.2/1.1]? V-Ic color index;
Mount Laguna Observatory 1m
78- 82 F5.3 mag e_V-Ic [0.001/0.3]? Uncertainty in V-Ic
84- 85 I2 --- mS71 ? Sanders (1971A&A....15..368S 1971A&A....15..368S)
membership probability
87- 88 I2 --- mU4 UCAC4 membership probability (Zacharias+
2013, I/322 and Dias+, J/A+A/564/A79)
90- 91 I2 --- mK13 ? Kharchenko membership probability
(2013, J/A+A/558/A53)
93- 93 A1 --- Frv Radial velocity flag (1)
95- 95 A1 --- Fpos Position membership flag (2)
97-123 A27 --- Notes Variability notes (3)
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Note (1): We report the radial velocity membership as follows:
Y = there is no significant variation in all of the measurements or an orbital
solution allows us to identify that the system velocity is consistent
with the cluster mean (∼7km/s).
B = there was significant radial velocity variation, but the system
could potentially be a cluster member ("B" for binary candidate).
N = there is little or no chance that the system is a member of the cluster.
See section 4.1 for further details.
Note (2): We give a simple position membership indication ("Y" or "N") based on
whether each star lies within or without 13' from the cluster center.
Note (3): Variability Identification References and notes. Square brackets
indicate earlier identifications we believe are incorrect.
B = Balona et al. (2011MNRAS.413.2403B 2011MNRAS.413.2403B);
D = Debosscher et al. (2011, J/A+A/529/A89);
T = Tkachenko et al. (2013, J/A+A/556/A52);
U = Uytterhoeven et al. (2011, J/A+A/534/A125);
vC = van Cauteren et al. (2005CoAst.146...21V 2005CoAst.146...21V);
L = Luo et al. (2009NewA...14..584L 2009NewA...14..584L);
1 = binary?;
2 = SB1? On blue hook?;
3 = [misc. (D)];
4 = HIP 96532;
5 = [β Cep (D)]; long P binary;
6 = [misc./rot. (D)];
7 = γ Dor (T), SPB (D);
8 = [β Cep (D)];
9 = SB1;
10 = Redward of MS;
11 = Suspected binary?;
12 = EB;
13 = EB (P=197.146d);
14 = [SPB (D)];
15 = [rotation/activity (U)];
16 = faint; nonmember?;
17 = TYC 3556-1768-1 is misidentified as Cl* NGC 6811 San 170 in SIMBAD;
18 = TYC 3556-1698-1 identified as proper motion member in
Baumgardt et al. (2000, J/A+AS/146/251).
21 = rotation/activity (U);
22 = HIP 96538;
23 = P=4.4177d;
25 = rot. (B);
26 = 1.5d variations;
27 = P=1.81329d;
28 = no obvious pulsation;
29 = act. (D);
30 = odd light curve;
31 = nonmember or triple?;
32 = P=204.471d;
33 = P=2.74405d; nonmember?;
34 = P=71.6619d;
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Jan-2017