J/ApJS/262/12 Kepler P<2d close binaries (Kobulnicky+, 2022)
A Bayesian analysis of physical parameters for 783 Kepler close binaries:
extreme-mass-ratio systems and a new mass ratio versus period lower limit.
Kobulnicky H.A., Molnar L.A., Cook E.M., Henderson L.E.
<Astrophys. J. Suppl. Ser., 262, 12 (2022)>
=2022ApJS..262...12K 2022ApJS..262...12K
ADC_Keywords: Binaries, eclipsing; Models; Effective temperatures; Photometry;
Spectra, optical
Keywords: Contact binary stars ; Close binary stars ;
Markov chain Monte Carlo ; Stellar evolution ; Multiple star evolution
Abstract:
Contact binary star systems represent the long-lived penultimate phase
of binary evolution. Population statistics of their physical
parameters inform an understanding of binary evolutionary pathways and
end products. We use light curves and new optical spectroscopy to
conduct a pilot study of ten (near) contact systems in the long-period
(P>0.5d) tail of close binaries in the Kepler field. We use PHOEBE
light-curve models to compute Bayesian probabilities on five principal
system parameters. Mass ratios and third-light contributions measured
from spectra agree well with those inferred from the light curves.
Pilot study systems have extreme mass ratios q<0.32. Most are triples.
Analysis of the unbiased sample of 783 0.15d<P<2d (near) contact
binaries results in 178 probable contact systems, 114 probable
detached systems, and 491 ambiguous systems for which we report
best-fitting and 16th-/50th-/84th-percentile parameters. Contact
systems are rare at periods P>0.5d, as are systems with q>0.8. There
exists an empirical mass ratio lower limit qmin(P)∼0.05-0.15 below
which contact systems are absent, supporting a new set of theoretical
predictions obtained by modeling the evolution of contact systems
under the constraints of mass and angular momentum conservation.
Premerger systems should lie at long periods and near this mass ratio
lower limit, which rises from q=0.044 for P=0.74d to q=0.15 at P=2.0d.
These findings support a scenario whereby nuclear evolution of the
primary (more massive) star drives mass transfer to the primary, thus
moving systems toward extreme q and larger P until the onset of the
Darwin instability at qmin precipitates a merger.
Description:
We assembled calibrated Kepler photometry on the targets available
from the public MAST archive as cleaned and detrended by
Kirk+ (2016, J/AJ/151/68). Data were generally available from a
majority of the Kepler operational quarters, from as few as seven to
as many as 17, yielding tens of thousands of measurements in the broad
Kepler bandpass spanning four years, from 2009 May through 2013 May.
We determined mean periods for each system.
We obtained optical spectra on the targets near each of the two
quadrature orbital phases (φ=[0.25,0.75]) with the long-slit
spectrographs at the Wyoming Infrared Observatory (WIRO) 2.3m
telescope (range 5400-6700Å and R∼4000) and/or the Apache Point
Observatory (APO) 3.5m telescope with the Double Imaging Spectrograph
(range 5800-6900Å and R∼3000). See Section 2.3.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table3.dat 83 783 Best parameters for contact, detached, and ambiguous
systems when modeled using contact configuration
table4.dat 103 783 Bayesian percentile parameters for contact, detached,
and ambiguous systems modeled using contact
configuration
table5.dat 100 114 Best parameters for probable detached systems modeled
with a detached configuration
table6.dat 121 114 Bayesian percentile parameters for probable
detached systems modeled with a detached
configuration
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
J/A+A/428/1001 : Limb-darkening law for LTE models. III. (Claret, 2004)
J/ApJ/629/1055 : Evolution of close binary systems (Yakut+, 2005)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/AJ/142/112 : KIC photometric calibration (Brown+, 2011)
J/AJ/149/49 : Radial velocities of AW UMa (Rucinski+, 2015)
J/AJ/151/68 : Kepler Mission. VII. Eclipsing binaries in DR3 (Kirk+, 2016)
J/AJ/156/241 : Variable stars measured by ATLAS (Heinze+, 2018)
J/A+A/623/A72 : Binarity of HIP stars from Gaia pm anomaly (Kervella+, 2019)
J/ApJS/262/10 : Kepler eclipsing binaries with Gaia data (Knote+, 2022)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC [1295531/12602985] Kepler Input Catalog identifier
10- 18 F9.7 d Per [0.13/1.98] Orbital period from
Kirk+ 2016, J/AJ/151/68
20- 32 F13.5 d T0 [2454862.14/2455182.8] Julian Date for superior
conjunction (1)
34- 38 I5 K Teff [3516/11064] KIC stellar effective temperature
40- 43 F4.2 --- Morph [0.7/1] Light curve morphology parameter as in
Kirk+ 2016, J/AJ/151/68
45- 48 F4.1 deg i [4.4/90] Orbital inclination angle of
best-fitting model
50- 54 F5.3 --- f [0.03/0.998] Fillout factor of best-fitting model
56- 60 F5.2 --- q [0.04/27.16] Mass ratio q=M2/M1 of best-fitting
model (2)
62- 66 F5.3 --- l3 [0/0.998] Third light fraction of best-fitting
model
68- 72 F5.3 --- T2/T1 [0.9/1.1] Temperature ratio of components of
best-fitting model
74- 81 F8.6 --- RMS [6e-6/0.06] RMS of best fitting model
83 A1 --- Flag Identification flag (G1)
--------------------------------------------------------------------------------
Note (1): Of the component producing the deeper eclipse, as in
Kirk+ (2016, J/AJ/151/68) or as updated in this work.
Note (2): Where M1 produces the deeper eclipse.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC [1295531/12602985] Kepler Input Catalog ID
10- 14 F5.3 deg cosi-16 [0.005/0.993] Cos(inclination) for 16th
percentile of Monte Carlo realizations
16- 20 F5.3 deg cosi-50 [0.02/0.994] Cos(inclination) for 50th
percentile of Monte Carlo realizations
22- 26 F5.3 deg cosi-84 [0.046/0.996] Cos(inclination) for 84th
percentile of Monte Carlo realizations
28- 32 F5.3 --- f-16 [0.03/0.99] Fillout factor for 16th
percentile of Monte Carlo realizations
34- 38 F5.3 --- f-50 [0.045/0.992] Fillout factor for 50th
percentile of Monte Carlo realizations
40- 44 F5.3 --- f-84 [0.06/0.996] Fillout factor for 84th
percentile of Monte Carlo realizations
46- 51 F6.3 --- logq-16 [-1.4/1.1] Log(Mass ratio) for 16th
percentile of Monte Carlo realizations (2)
53- 58 F6.3 --- logq-50 [-1.24/1.2] Log(Mass ratio) for 50th
percentile of Monte Carlo realizations (2)
60- 65 F6.3 --- logq-84 [-1.12/1.5] Log(Mass ratio) for 84th
percentile of Monte Carlo realizations (2)
67- 71 F5.3 --- l3-16 [0.003/0.997] Fraction of third light for
16th percentile of Monte Carlo realizations
73- 77 F5.3 --- l3-50 [0.008/0.997] Fraction of third light for
50th percentile of Monte Carlo realizations
79- 83 F5.3 --- l3-84 [0.016/0.998] Fraction of third light for
84th percentile of Monte Carlo realizations
85- 89 F5.3 --- T2/T1-16 [0.95/1.05] Component temperature ratios for
16th percentile of Monte Carlo realizations
91- 95 F5.3 --- T2/T1-50 [0.95/1.05] Component temperature ratios for
50th percentile of Monte Carlo realizations
97- 101 F5.3 --- T2/T1-84 [0.95/1.06] Component temperature ratios for
84th percentile of Monte Carlo realizations
103 A1 --- Flag Identification flag (G1)
--------------------------------------------------------------------------------
Note (2): Where q=M2/M1 and M1 produces the deeper eclipse.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC [1868650/12598713] Kepler Input Catalog ID
10- 18 F9.7 d Per [0.16/1.97] Orbital period from
Kirk+ 2016, J/AJ/151/68
20- 32 F13.5 d T0 [2454949.9/2455114] Julian Date for superior
conjunction (1)
34- 38 I5 K Teff [4834/11064] Kepler Input catalog stellar
effective temperature
40- 43 F4.2 --- Morph [0.7/1] Light curve morphology parameter as
in Kirk+ 2016, J/AJ/151/68
45- 48 F4.1 deg i [16.9/89.5] Orbital inclination angle of
best-fitting model
50- 55 F6.3 --- q [0.03/29.9] Mass ratio q=M2/M1 of
best-fitting model (2)
57- 61 F5.3 --- l3 [0.007/0.996] Third light fraction of
best-fitting model
63- 67 F5.3 --- T2/T1 [0.7/1.12] Temperature ratio of components of
best-fitting model
69- 72 F4.2 Rsun R1 [0.19/3.4] Equivalent radius for component 1
of best-fitting model
74- 77 F4.2 --- R2/R1 [0.2/5.1] Ratio of component equivalent
radii, R2equiv/R1equiv of best-fitting model
79- 83 F5.3 --- R1/R1max [0.129/1] The R1equiv/R1max ratio of
best-fitting model (G2)
85- 89 F5.3 --- R2/R2max [0.05/0.99] The R2equiv/R2max ratio of
best-fitting model (G2)
91- 98 F8.6 --- RMS [1.6e-5/0.004] RMS of best fitting model
100 A1 --- Flag Identification flag
(always "D"=Detached system)
--------------------------------------------------------------------------------
Note (1): Of the component producing the deeper eclipse, as in
Kirk+ (2016, J/AJ/151/68) or as updated in this work.
Note (2): Where M1 produces the deeper eclipse.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 I8 --- KIC [1868650/12598713] Kepler Input Catalog ID
10- 14 F5.3 deg cosi-16 [0.016/0.95] Cos(inclination) for 16th
percentile of Monte Carlo realizations
16- 20 F5.3 deg cosi-50 [0.04/0.96] Cos(inclination) for 50th
percentile of Monte Carlo realizations
22- 26 F5.3 deg cosi-84 [0.08/0.97] Cos(inclination) for 84th
percentile of Monte Carlo realizations
28- 33 F6.3 --- logq-16 [-1.6/1.16] Log(Mass ratio) for 16th
percentile of Monte Carlo realizations (1)
35- 40 F6.3 --- logq-50 [-1.45/1.24] Log(Mass ratio) for 50th
percentile of Monte Carlo realizations (1)
42- 47 F6.3 --- logq-84 [-1.34/1.34] Log(Mass ratio) for 84th
percentile of Monte Carlo realizations (1)
49- 53 F5.3 --- l3-16 [0.006/0.992] Fraction of third light for
16th percentile of Monte Carlo realizations
55- 59 F5.3 --- l3-50 [0.018/0.994] Fraction of third light for
50th percentile of Monte Carlo realizations
61- 65 F5.3 --- l3-84 [0.03/0.996] Fraction of third light for 84th
percentile of Monte Carlo realizations
67- 71 F5.3 --- T2/T1-16 [0.7/1.14] Component temperature ratios for
16th percentile of Monte Carlo realizations
73- 77 F5.3 --- T2/T1-50 [0.7/1.3] Component temperature ratios for
50th percentile of Monte Carlo realizations
79- 83 F5.3 --- T2/T1-84 [0.7/1.4] Component temperature ratios for
84th percentile of Monte Carlo realizations
85- 89 F5.3 --- R1-16 [0.18/3.4] Radius of component 1 for 16th
percentile of Monte Carlo realizations (G2)
91- 95 F5.3 --- R1-50 [0.2/3.4] Radius of component 1 for 50th
percentile of Monte Carlo realizations (G2)
97- 101 F5.3 --- R1-84 [0.25/3.4] Radius of component 1 for 84th
percentile of Monte Carlo realizations (G2)
103- 107 F5.3 --- R2/R1-16 [0.2/4.6] Component equivalent radii ratios
for 16th percentile of Monte Carlo
realizations (G2)
109- 113 F5.3 --- R2/R1-50 [0.2/5.1] Component equivalent radii ratios
for 50th percentile of Monte Carlo
realizations (G2)
115- 119 F5.3 --- R2/R1-84 [0.2/5.8] Component equivalent radii ratios
for 84th percentile of Monte Carlo
realizations (G2)
121 A1 --- Flag Identification flag
(always "D"=Detached system)
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Note (1): Where q=M2/M1 and M1 produces the deeper eclipse.
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Global notes:
Note (G1): Denotes probable identification according to criteria in the text.
Flag as follows:
C = Contact system (178 occurrences);
D = Detached system (114 occurrences);
A = Ambiguous case (491 occurrences).
Note (G2): These are approximate values predicated on the assumption of
1 solar mass for the more massive component in the system. R1max and
R2max scale weakly with the adopted M1. R1 is the radius of a
spherical star having equivalent surface area to the tidally distorted
star. R1max is the equivalent radius of a tidally distorted star of
maximum possible size without overflow.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 15-Nov-2022