J/ApJ/820/1 Kepler light curve of the EB star KIC 9532219 (Lee+, 2016)
The varying light curve and timings of the ultrashort-period contact binary
KIC 9532219.
Lee J.W., Hong K., Koo J.-R., Park J.-H.
<Astrophys. J., 820, 1 (2016)>
=2016ApJ...820....1L 2016ApJ...820....1L (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry ; Stars, variable
Keywords: binaries: close; binaries: eclipsing; stars: fundamental parameters;
stars: individual: KIC 9532219; sunspots
Abstract:
KIC 9532219 is a W UMa-type eclipsing binary with an orbital period of
0.1981549days that is below the short-period limit (∼0.22days) of the
period distribution for contact binaries. The Kepler light curve of
the system exhibits striking changes in both eclipse depths and light
maxima. Applying third-body and spot effects, the light-curve
synthesis indicates that the eclipsing pair is currently in a marginal
contact stage with a mass ratio of q=1.20, an orbital inclination of
i=66.0°, a temperature difference of T1-T2=172K, and a third
light of l3=75.9%. To understand the light variations with time, we
divided up the light curve into 312 segments and analyzed them
separately. The results reveal that variation of eclipse depth is
primarily caused by changing amounts of contamination due to the
nearby star KIC 9532228 between the Kepler Quarters and that the
variable O'Connell effect originates from the starspot activity on the
less massive primary component. Based on our light-curve timings, a
period study of KIC 9532219 indicates that the orbital period has
varied as a combination of a downward parabola and a light-travel-time
(LTT) effect due to a third body, which has a period of 1196 days and
a minimum mass of 0.0892M☉ in an orbit of eccentricity 0.150.
The parabolic variation could be a small part of a second LTT orbit
due to a fourth component in a wider orbit, instead of either mass
transfer or angular momentum loss.
Description:
The Kepler observations of KIC 9532219 were obtained during Quarters
3-17 (Sept 2009 to Apr 2013) in long cadence (LC) mode with samples
taken every 29.4 minutes. We downloaded and analyzed the original data
from the Kepler archive, but the results are not much different from
the detrended light curves in the Kepler EB catalog (Prsa et al. 2011,
J/AJ/141/83; superseded by J/AJ/142/160).
Objects:
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RA (ICRS) DE Designation(s) (Period)
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19 36 52.01 +46 10 48.8 KIC 9532219 = BOKS 25301 (P=0.1981549)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 312 Light levels of KIC 9532219 at four characteristic
phases
table3.dat 72 312 Light-curve solutions for the 312 datasets combined
at intervals of 20 orbital periods
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/AJ/149/197 : Minima of 10 Kepler eclipsing binaries (Zasche+, 2015)
J/AJ/149/93 : Eclipse timings of KIC 5621294 (Lee+, 2015)
J/MNRAS/452/3561 : Kepler eclipsing binary stars. K2 (LaCourse+, 2015)
J/MNRAS/437/3473 : Temperatures of Kepler eclipsing binaries (Armstrong+, 2014)
J/PASP/126/914 : Kepler eclipsing binary stars. V. (Conroy+, 2014)
J/ApJS/211/2 : Revised properties of Q1-16 Kepler targets (Huber+, 2014)
J/AJ/148/37 : Long-term photometric behavior of V404 Lyr (Lee+, 2014)
J/AJ/147/45 : Kepler mission IV. Close binaries (Conroy+, 2014)
J/AJ/144/24 : The Kepler-INT survey (Greiss+, 2012)
J/AJ/143/137 : Minima of eclipsing binaries from Kepler (Gies+, 2012)
J/AJ/142/160 : Kepler Mission. II. eclipsing binaries (Slawson+, 2011)
J/AJ/142/2 : Burrell-Optical-Kepler-Survey (BOKS). I. (Feldmeier+, 2011)
J/AJ/141/83 : Eclipsing binaries in Kepler 1st data release (Prsa+, 2011)
J/AJ/141/78 : Low-mass eclipsing binaries in KIC (Coughlin+, 2011)
J/AJ/138/478 : AR Boo differential BVR photometry (Lee+, 2009)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/A+A/450/681 : Companions to close spectroscopic bin. (Tokovinin+, 2006)
http://keplerebs.villanova.edu/ : Kepler eclipsing binaries catalog
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Mean Barycentric Julian Date of observation (1)
15- 20 F6.3 mag minI [16.17/16.2] Kepler magnitude at phase 0.0
22- 26 F5.3 mag e_minI [0/0.03] Uncertainty in minI
28- 33 F6.3 mag maxI [16.1/16.11] Kepler magnitude at phase 0.25
35- 39 F5.3 mag e_maxI [0/0.03] Uncertainty in maxI
41- 46 F6.3 mag minII [16.16/16.2] Kepler magnitude at phase 0.5
48- 52 F5.3 mag e_minII [0/0.03] Uncertainty in minI
54- 59 F6.3 mag maxII [16.1/16.11] Kepler magnitude at phase 0.75
61- 65 F5.3 mag e_maxII [0/0.03] Uncertainty in maxII
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Note (1): The mean time was computed by averaging starting and ending BJDs
of the observations.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric Julian Date of observation
16- 21 F6.2 deg lambda [53.1/310.8] Longitude of spot center
23- 27 F5.2 deg rs [10.7/16] Angular radius
29- 33 F5.3 --- Ts [0.8/1] Spot temperature factor (1)
35- 39 F5.2 deg i [64.6/68] Orbital inclination
41- 44 I4 K T1 [5158/5225] Primary's effective temperature
46- 51 F6.4 --- Omega1 [4.06/4.09] Primary's potential
53- 58 F6.4 --- q [1.19/1.21] Mass ratio
60- 65 F6.4 --- l1 [0.10/0.15] Primary's light contribution
67- 72 F6.4 --- l3 [0.7/0.8] Third light contribution
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Note (1): Where Ts=Tspot/Tlocal.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 30-May-2016