J/A+A/590/A85 Massive LMC eclipsing binaries minima timings (Zasche+, 2016)
The first study of the light-travel time effect in massive LMC
eclipsing binaries.
Zasche P., Wolf M., Vrastil J., Pilarcik L., Jurysek J.
<Astron. Astrophys. 590, A85 (2016)>
=2016A&A...590A..85Z 2016A&A...590A..85Z (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Binaries, eclipsing
Keywords: binaries: eclipsing - stars: early-type -
stars: fundamental parameters - Magellanic Clouds
Abstract:
New CCD observations for semidetached and detached eclipsing binaries
from the Large Magellanic Cloud were carried out using the Danish
1.54-m telescope located at the La Silla Observatory in Chile. The
selected systems were monitored for their times of minima, which were
required to be able to study the period changes taking place in them.
In addition, many new times of minima were derived from the
photometric surveys OGLE-II, OGLE-III, and MACHO.
The O-C diagrams of minima timings were analysed using the
hypothesis of the light-travel time effect, i.e. assuming the orbital
motion around a common barycenter with the distant component.
Moreover, the light curves of these systems were also analysed using
the program PHOEBE, which provided the physical parameters of the
stars.
Description:
For the first time, in this study we derived the relatively short
periods of modulation in these systems, which relates to third bodies.
The orbital periods resulted from 3.6 to 11.3yr and the
eccentricities were found to be up to 0.64. This is the first time
that this kind of analysis for the set of extragalactic sources has
been performed. The Wolf-Rayet system OGLE-LMC-ECL-08823 is the most
mysterious one, owing to the resultant high mass function. Another
system, OGLE-LMC-ECL-19996, was found to contain a third body with a
very high mass (M3,min=26M☉). One system (OGLE-LMC-ECL-09971)
is suspicious because of its eccentricity, and another one
(OGLE-LMC-ECL-20162) shows some light curve variability, with a
possible flare-like or microlensing-like event.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 42 8 List of studied stars
table4.dat 65 305 List of the minima timings used for the analysis
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See also:
J/AJ/134/1963 : MC eclipsing binaries MACHO r,b light curves (Faccioli+, 2007)
J/AcA/54/1 : OGLE II SMC eclipsing binaries (Wyrzykowski+, 2004)
J/AcA/61/103 : VI light curves of LMC eclipsing binaries (Graczyk+, 2011)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- --- [OGLE-LMC-ECL-]
14- 18 I05 --- Star Star number (OGLE-LMC-ECL-NNNNN)
20- 21 I2 h RAh Simbad Right ascension (J2000)
23- 24 I2 min RAm Simbad Right ascension (J2000)
26- 30 F5.2 s RAs Simbad Right ascension (J2000)
32 A1 --- DE- Simbad declination sign (J2000)
33- 34 I2 deg DEd Simbad declination (J2000)
36- 37 I2 arcmin DEm Simbad declination (J2000)
39- 42 F4.1 arcsec DEs Simbad declination (J2000)
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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- 13 A13 --- --- [OGLE-LMC-ECL-]
14- 18 I05 --- Star Star number (OGLE-LMC-ECL-NNNNN)
21- 31 F11.5 d HJD Heliocentric Julian Date of Minimum (HJD-2400000)
35- 41 F7.5 d e_HJD Error of HJD
45- 48 A4 --- Type Type of Minimum (primary/secondary)
52- 54 A3 --- Filter Filter used
58- 65 A8 --- Ref Source/Observatory (1)
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Note (1): References as follows:
MACHO = Faccioli et al., 2007, Cat. J/AJ/134/1963
OGLE II = Wyrzykowski et al., 2004, Cat. J/AcA/54/1
OGLE III = Graczyk et al., 2011, Cat. J/AcA/61/103
DK154 = Danish 1.54-meter telescope, located on La Silla
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Acknowledgements:
Petr Zasche, petr.zasche(at)email.cz
(End) Patricia Vannier [CDS] 18-Apr-2016