J/ApJ/824/15 Orbital circularization of Kepler eclipsing bin. (Van Eylen+, 2016)
Orbital circularization of hot and cool Kepler eclipsing binaries.
Van Eylen V., Winn J.N., Albrecht S.
<Astrophys. J., 824, 15-15 (2016)>
=2016ApJ...824...15V 2016ApJ...824...15V (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Effective temperatures
Keywords: binaries: eclipsing;
planets and satellites: dynamical evolution and stability
stars: evolution; stars: fundamental parameters
Abstract:
The rate of tidal circularization is predicted to be faster for
relatively cool stars with convective outer layers, compared to hotter
stars with radiative outer layers. Observing this effect is
challenging because it requires large and well-characterized samples
that include both hot and cool stars. Here we seek evidence of the
predicted dependence of circularization upon stellar type, using a
sample of 945 eclipsing binaries observed by Kepler. This sample
complements earlier studies of this effect, which employed smaller
samples of better-characterized stars. For each Kepler binary we
measure e.cos.ω based on the relative timing of the primary and
secondary eclipses. We examine the distribution of e.cos.ω as a
function of period for binaries composed of hot stars, cool stars, and
mixtures of the two types. At the shortest periods, hot-hot binaries
are most likely to be eccentric; for periods shorter than four days,
significant eccentricities occur frequently for hot-hot binaries, but
not for hot-cool or cool-cool binaries. This is in qualitative
agreement with theoretical expectations based on the slower
dissipation rates of hot stars. However, the interpretation of our
results is complicated by the largely unknown ages and evolutionary
states of the stars in our sample.
Description:
To create our sample we begin with the EB catalog by Slawson et al.
(2011, J/AJ/142/160). We use the periods given in this catalog. We
rely on the effective temperatures for the primary and secondary
stars, T1 and T2, which were determined by Armstrong et al. (2014,
J/MNRAS/437/3473) by fitting the observed spectral energy
distribution. We impose the restriction Teff≤10000K, to limit the
number of very young stars in the sample.
Kepler observations from all quarters were used to determine the times
of the primary and secondary eclipses.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 68 983 System parameters for Kepler eclipsing binaries
with measured e.cos(ω) values
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See also:
V/133 : Kepler Input Catalog (Kepler Mission Team, 2009)
J/MNRAS/437/3473 : Temperatures of Kepler eclipsing binaries (Armstrong+, 2014)
J/ApJ/757/18 : RVs for 16 hot Jupiter host stars (Albrecht+, 2012)
J/AJ/142/160 : Kepler Mission. II. eclipsing binaries (Slawson+, 2011)
J/AJ/141/83 : Eclipsing binaries in Kepler DR1 (Prsa+, 2011)
J/AJ/141/78 : Low-mass eclipsing binaries in KIC (Coughlin+, 2011)
J/other/A+ARV/18.67 : Accurate masses and radii of normal stars (Torres+, 2010)
J/MNRAS/401/257 : Early-type binaries on main sequence (Khaliullin+, 2010)
J/A+A/450/681 : Companions to close spectroscopic bin. (Tokovinin+, 2006)
http://keplerebs.villanova.edu/ : Kepler eclipsing binaries online catalog
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 I8 --- KIC Kepler Input Catalog identifier
10- 17 F8.5 d Per [1.5/50] Period
19- 29 F11.5 d HJD [5500.4/55733.8] Heliocentric Julian Date (1)
31- 35 I5 K Teff1 [3510/26640] Primary effective temperature
37- 41 I5 K e_Teff1 [350/13408] Uncertainty in Teff1
43- 47 I5 K Teff2 [3516/26819] Secondary effective temperature
49- 53 I5 K e_Teff2 [540/13410] Uncertainty in Teff2
55- 61 F7.4 --- ecos(w) [-0.72/0.7] Eccentricity and cosine of
argument of pericenter (2)
63- 68 F6.4 --- e_ecos(w) [0.0002/0.3] Uncertainty in ecos(w)
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Note (1): BJD0 of "5500.426884" as given in
http://keplerebs.villanova.edu/overview/?k=3544694 for KIC 3544694;
note added by CDS.
Note (2): Equation (1): ecosω~((π(t2-t1))/2P)-π/4 where P is
the orbital period; t1 is the approximate time of the deepest eclipse
and t2 is the approximate time of the second eclipse.
See section 2 for further explanations.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 10-Aug-2016