J/AJ/152/57 VRI light curves of four contact binaries (Djurasevic+, 2016)
A photometric study of four recently discovered contact binaries: 1SWASP
J064501.21+342154.9, 1SWASP J155822.10-025604.8, 1SWASP J212808.86+151622.0, and
UCAC4 436-062932.
Djurasevic G., Essam A., Latkovic O., Cseki A., El-Sadek M.A.,
Abo-Elala M.S., Hayman Z.M.
<Astron. J., 152, 57 (2016)>
=2016AJ....152...57D 2016AJ....152...57D (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry, VRI
Keywords: binaries: eclipsing - stars: fundamental parameters -
stars: individual (1SWASP J064501.21+342154.9,
1SWASP J155822.10-025604.8, 1SWASP J212808.86+151622,
UCAC4 436-062932)
Abstract:
We present new, high-quality multicolor observations of four recently
discovered contact binaries, 1SWASP J064501.21+342154.9, 1SWASP
J155822.10-025604.8, 1SWASP J212808.86+151622.0, and UCAC4 436-062932,
and analyze their light curves to determine orbital and physical
parameters using the modeling program of G. Djurasevic. In the absence
of spectroscopic observations, the effective temperatures of the
brighter components are estimated from the color indices, and the mass
ratios are determined with the q-search method. The analysis shows
that all four systems are W UMa type binaries in shallow contact
configurations, consisting of late-type main-sequence primaries and
evolved secondaries with active surface regions (dark or bright spots)
resulting from magnetic activity or ongoing transfer of thermal energy
between the components. We compare the derived orbital and stellar
parameters for these four variables with a large sample of previously
analyzed W UMa stars and find that our results fit it well.
Description:
Photometric observations of selected variables were carried out with
the wide Bessell V, R, and I passbands closely matched to the classic
Johnson-Cousins system, using the back-illuminated EEV CCD 42-40
camera with 2048*2048 pixels. The pixel size, scale, and total field
of view are 13.5µ, 0.305''/pixel, and 10*10arcmin2, respectively.
The camera is attached to the Newtonian focus (f/4.84) of the 1.88m
reflector telescope of the Kottamia Astronomical Observatory (KAO) in
Egypt, and kept at a temperature of -125° by liquid nitrogen
cooling. Exposure times for J0645 were 60, 20, and 10 s for the V, R,
and I passbands, respectively; 150, 80, and 60s for J1558 and UCAC4;
and 100, 40, and 20s for J2128.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 12 Summary of observational aspects
table3.dat 59 1670 BVRI photometry of J0645, J1558, J2128, and UCAC4
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
I/297 : NOMAD Catalog (Zacharias+ 2005)
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
V/120 : Catalog of early-type contact binaries (Bondarenko+, 1996)
J/AJ/148/126 : Light curves of 4 overcontact binaries (Caliskan+, 2014)
J/A+A/525/A66 : 4 close binaries BVR light curves (Djurasevic+, 2011)
J/other/PASA/23.154 : Light curves of XY Leo, EE Cet, AQ Psc (Djurasevic+ 2006)
J/A+A/415/283 : BV light curves of NN Vir (Djurasevic+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- Object Star short name
7- 16 A10 --- Star Star role (Variable, Comparison, or Check)
18- 43 A26 --- Name Star name (1)
45- 63 A19 --- OName Other name (1)
65- 66 I2 h RAh Hour of Right Ascension (J2000) (1)
68- 69 I2 min RAm Minute of Right Ascension (J2000) (1)
71- 75 F5.2 s RAs Second of Right Ascension (J2000) (1)
77 A1 --- DE- Sign of the Declination (J2000) (1)
78- 79 I2 deg DEd Degree of Declination (J2000) (1)
81- 82 I2 arcmin DEm Arcminute of Declination (J2000) (1)
84- 88 F5.2 arcsec DEs Arcsecond of Declination (J2000) (1)
90- 95 F6.3 mag Bmag [13.2/16.2] The B-band magnitude (1)
97-102 F6.3 mag Vmag [12.3/15.1] The V-band magnitude (1)
104-112 F9.7 d Per [0.22/0.37]? Orbital period (2)
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Note (1): Information about the variable, comparison, and check stars was
obtained from the UCAC4 catalog (Zacharias et al. 2012, Cat. I/322), and
the NOMAD catalog (Zacharias et al. 2005, Cat. I/297).
Note (2): From Tables 4-7 in the paper.
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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- 26 A26 --- Name Star identifier (1)
28 A1 --- Flt [VRI] Filter used in the observation
(Johnson-Cousins V, R or I)
30- 42 F13.5 d HJD Heliocentric Julian Date of observation
44- 51 F8.5 mag dmag [-0.49/3.1] Differential magnitude in filter
(variable minus comparison)
53- 59 F7.5 mag e_dmag [0.0018/0.28] Standard deviation in dmag
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Note (1): 1SWASP J064501.21+342154.9 (J0645), 1SWASP J155822.10-025604.8
(J1558), 1SWASP J212808.86+151622.0 (J2128), or UCAC4 436-062932 (UCAC4).
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 23-Sep-2016