J/AJ/143/122 VR light curves of CK Boo (Yang+, 2012)
Deep, low-mass ratio overcontact binary systems.
XII. CK Bootis with possible cyclic magnetic activity and additional companion.
Yang Y.-G., Qian S.-B., Soonthornthum B.
<Astron. J., 143, 122 (2012)>
=2012AJ....143..122Y 2012AJ....143..122Y
ADC_Keywords: Binaries, eclipsing ; Photometry, VRI ; Photometry, CCD
Keywords: binaries: close - binaries: eclipsing - stars: individual (CK Bootis)
Abstract:
We present precision CCD photometry, a period study, and a two-color
simultaneous Wilson code solution of the short-period contact binary
CK Bootis. The asymmetric light curves were modeled by a dark spot on
the primary component. The result identifies that CK Boo is an A-type
W UMa binary with a high fillout of f=71.7(±4.4)%. From the O-C
curve, it is found that the orbital period changes in a complicated
mode, i.e., a long-term increase with two sinusoidal variations. One
cyclic oscillation with a period of 10.67(±0.20)yr may result from
magnetic activity cycles, which are identified by the variability of
Max. I-Max. II. Another sinusoidal variation (i.e.,
A=0.0131days(±0.0009days) and P3=24.16(±0.64)yr) may be attributed
to the light-time effect due to a third body. This kind of additional
companion can extract angular momentum from the central binary system.
The orbital period secularly increases at a rate of
dP/dt=+9.79(±0.80)*10^-8days/yr, which may be interpreted by
conservative mass transfer from the secondary to the primary. This
kind of deep, low-mass ratio overcontact binaries may evolve into a
rapid-rotating single star, only if the contact configuration do not
break down at Jspin>(1/3)Jorb.
Description:
New CCD photometry of CK Boo was performed on 2011 June 4, 13, and 17,
and on 2010 April 27, using the 85cm telescope at the Xinglong station
of National Astronomical Observatories of China (NAOC). This telescope
was equipped with a multicolor CCD photometric system on the primary
focus. A standard Johnson-Cousin-Bessel set of UBVRcIc filters was
applied. In 2011, we obtained a total of 553 images in V band and 551
images in R band.
Together with our eclipse times, we compiled a total of 106 light
minimum times (86 photoelectric measurements and 20 CCD ones).
Objects:
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RA (2000) DE Designation(s) (Period)
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14 35 03.76 +09 06 49.4 CK Bootis = V* CK Boo (P=0.35515)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 39 553 VR Photometric Observations of CK Boo in 2011
table2.dat 33 19 New obtained light minimum times of CK Boo
table3.dat 48 106 All available light minimum times of CK Boo
refs.dat 76 25 References
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2013)
J/A+A/546/A69 : Orbits of visual binaries & dynamical masses (Malkov+, 2012)
J/MNRAS/412/1787 : Physical parameters of 62 eclipsing binaries (Deb+, 2011)
J/AJ/142/117 : UBVrcIc differential photometry of V1853 Ori (Samec+, 2011)
J/MNRAS/412/1787 : Physical parameters of 62 eclipsing binaries (Deb+, 2011)
J/AJ/134/2353 : Observations of contact binaries (Rucinski+, 2007)
J/A+A/446/785 : Catalogue of eclipsing variables (Malkov+, 2006)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/MNRAS/357/497 : Kinematics of W UMa-type binaries (Bilir+, 2005)
J/A+A/426/1001 : Catalog of contact binary stars (Csizmadia+, 2004)
J/AcA/54/207 : Ephemerids of eclipsing binaries (Kreiner, 2004)
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD-V Heliocentric Julian Date of V band observation
14- 19 F6.3 mag DVmag Differential V band magnitude (1)
21- 32 F12.4 d HJD-R ? Heliocentric Julian Date of R band
observation
34- 39 F6.3 mag DRmag ? Differential R band magnitude (1)
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Note (1): Typical precision of the variable star differential magnitudes is less
than 0.005mag per measurement.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date (1)
15- 21 F7.5 d e_HJD Uncertainty on HJD
23- 24 A2 --- Min [I/II] Minimum type (I=primary, II=secondary)
26 A1 --- Filt [BVRI] Photometric filter (B, V, R or I)
28- 33 A6 --- Tel Telescope used
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Note (1): The first 10 light minimum times for CK Boo were calculated from
the observations of Gazeas et al. (2006AcA....56..127G 2006AcA....56..127G).
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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- 12 F12.4 d HJD Heliocentric Julian Date
14- 16 A3 --- Meth Detection method (pe=photoelectric or CCD)
18- 25 F8.1 --- Epoch Epoch
27- 28 A2 --- Min [I/II] Minimum type (I=primary, II=secondary)
30- 36 F7.4 d (O-C)1 The (O-C)1 value of the eclipse time (1)
38 A1 --- f_(O-C)2 [d] Discarded (O-C)2 value (2)
39- 45 F7.4 d (O-C)2 ? The (O-C)2 value of the eclipse time (3)
47- 48 A2 --- Ref Reference (in refs.dat file)
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Note (1): Computed using a linear ephemeris given by
Kreiner et al. (2001, http://www.as.up.krakow.pl/o-c/):
MinI=HJD2446183.595+0.3551532d*E, where E stands for epoch number.
See Section 3 for further explanations.
Note (2): Flag as follows:
d = discarded (photoelectric light minimum time HJD2447304.428 from
Diethelm, 1988BBSAG..88....7D 1988BBSAG..88....7D was discarded due to much larger scatter
(i.e., -0.0305).
Note (3): See equation (2) in Section 3.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 43 A20 --- Aut Author's name
45- 76 A32 --- Com Comments
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History:
From electronic version of the journal
References:
Qian & Yang Paper I. 2004AJ....128.2430Q 2004AJ....128.2430Q
Zhu et al. Paper II. 2005AJ....129.2806Z 2005AJ....129.2806Z
Qian et al. Paper III. 2005AJ....130..224Q 2005AJ....130..224Q
Yang et al. Paper IV. 2005AJ....130.2252Y 2005AJ....130.2252Y Cat. J/AJ/130/2252
Qian et al. Paper V. 2005AJ....130.1206Q 2005AJ....130.1206Q
Qian et al. Paper VI. 2006AJ....131.3028Q 2006AJ....131.3028Q
Qian et al. Paper VII. 2007AJ....134.1475Q 2007AJ....134.1475Q
Qian et al. Paper VIII. 2008AJ....136.1940Q 2008AJ....136.1940Q
Yang et al. Paper IX. 2009AJ....138..540Y 2009AJ....138..540Y
Qian et al. Paper X. 2011AJ....141..151Q 2011AJ....141..151Q
Zhu et al. Paper XI. 2011AJ....142..124Z 2011AJ....142..124Z
Yang et al., Paper XIII 2013AJ....146...35Y 2013AJ....146...35Y Cat. J/AJ/146/35
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 17-Jun-2013