J/A+A/578/A136 Period changes in SuperWASP eclipsing binaries (Lohr+, 2015)
Orbital period changes and the higher-order multiplicity fraction amongst
SuperWASP eclipsing binaries.
Lohr M.E., Norton A.J., Payne S.G., West R.G., Wheatley P.J.
<Astron. Astrophys. 578, A136 (2015)>
=2015A&A...578A.136L 2015A&A...578A.136L
ADC_Keywords: Binaries, eclipsing ; Stars, variable ; Photometry, CCD
Keywords: stars: variables: general - binaries: close - binaries: eclipsing
Abstract:
Orbital period changes of binary stars may be caused by the presence
of a third massive body in the system. Here we have searched the
archive of the Wide Angle Search for Planets (SuperWASP) project for
evidence of period variations in 13927 eclipsing binary candidates.
Sinusoidal period changes, strongly suggestive of third bodies, were
detected in 2% of cases; however, linear period changes were observed
in a further 22% of systems. We argue on distributional grounds that
the majority of these apparently linear changes are likely to reflect
longer-term sinusoidal period variations caused by third bodies, and
thus estimate a higher-order multiplicity fraction of 24% for
SuperWASP binaries, in good agreement with other recent figures for
the fraction of triple systems amongst binary stars in general.
Description:
Orbital period and period change measurements derived from SuperWASP
archival photometry are presented here for candidate eclipsing
binaries in three categories based on light curve morphology: EA, EB
and EW-type systems. Also listed are candidate systems exhibiting
sinusoidal or semi-sinusoidal period variation, whose O-C diagram
curves could not be well-fitted by either linear or quadratic
functions.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 94 388 EW systems with linear period changes
tablea2.dat 77 92 EW systems with sinusoidal period changes
tablea3.dat 94 137 EB systems with linear period changes
tablea4.dat 77 30 EB systems with sinusoidal period changes
tablea5.dat 94 172 EA systems with linear period changes
tablea6.dat 77 17 EA systems with sinusoidal period changes
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Byte-by-byte Description of file: tablea1.dat tablea3.dat tablea5.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- 1SWASP SuperWASP identifier (JHHMMSS.ss+DDMMSS.s)
21 A1 --- f_1SWASP [d] Object is duplicate of neighbour(s)
23- 24 I2 h RAh Right ascension (J2000) from 1SWASP ID
26- 27 I2 min RAm Right ascension (J2000) from 1SWASP ID
29- 33 F5.2 s RAs Right ascension (J2000) from 1SWASP ID
35 A1 --- DE- Declination sign (J2000) from 1SWASP ID
37- 38 I2 deg DEd Declination (J2000) from 1SWASP ID
40- 41 I2 arcmin DEm Declination (J2000) from 1SWASP ID
43- 46 F4.1 arcsec DEs Declination (J2000) from 1SWASP ID
48- 58 F11.4 s Per [10084/502168] Orbital period
60- 65 F6.4 s e_Per [0.0006/0.5] Uncertainty in orbital period
67- 74 F8.5 s/yr Pch [-6.5/4.6] Period change from quadratic fit
76- 82 F7.5 s/yr e_Pch [9e-05/1] Uncertainty in period change
84- 88 F5.2 --- Lchi Reduced χ2 for best linear O-C fit
90- 94 F5.2 --- Qchi Reduced χ2 for best quadratic O-C fit
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Byte-by-byte Description of file: tablea2.dat tablea4.dat tablea6.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- 1SWASP SuperWASP identifier (JHHMMSS.ss+DDMMSS.s)
21 A1 --- f_1SWASP [d] Object is duplicate of neighbour(s)
23- 24 I2 h RAh Right ascension (J2000) from 1SWASP ID
26- 27 I2 min RAm Right ascension (J2000) from 1SWASP ID
29- 33 F5.2 s RAs Right ascension (J2000) from 1SWASP ID
35 A1 --- DE- Declination sign (J2000) from 1SWASP ID
37- 38 I2 deg DEd Declination (J2000) from 1SWASP ID
40- 41 I2 arcmin DEm Declination (J2000) from 1SWASP ID
43- 46 F4.1 arcsec DEs Declination (J2000) from 1SWASP ID
48- 58 F11.4 s Per [10084/502168] Orbital period
60- 65 F6.4 s e_Per [9e-05/1] Uncertainty in orbital period
67- 71 F5.2 --- Lchi Reduced χ2 for best linear O-C fit
73- 77 F5.2 --- Qchi Reduced χ2 for best quadratic O-C fit
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Acknowledgements:
Marcus Lohr, Marcus.Lohr(at)open.ac.uk
(End) Marcus Lohr [OU, UK], Patricia Vannier [CDS] 15-May-2015