J/other/NewA/55.13 UY UMa and EF Boo compiled time of minima (Yu+, 2017)
Orbital period variations of two W UMa-type binaries: UY UMa and EF Boo.
Yu Y.-X., Zhang X.-D., Hu K., Xiang F.-Y.
<New Astron., 55, 13-16 (2017)>
=2017NewA...55...13Y 2017NewA...55...13Y (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing
Keywords: stars: binaries: close - stars: binaries: eclipsing -
stars: individual: UY UMa - stars: individual: EF Boo
Abstract:
The orbital period variations of two W UMa-type contact binaries,
UY UMa and EF Boo, are analyzed by using all available times of light
minimum. It is detected that the general trends of their (O-C) curves
show an upward parabolic variation, which reveals their continuous
period increases at the rates of dP/dt=2.545x10-7days/yr and
dP/dt=2.623x10-7days/yr respectively. Meanwhile, UY UMa also shows a
cyclic period variation with a small amplitude of A=0.0026-days
superposed on the long-term increase. Due to their contact
configurations, the secular period increases are interpreted as a
result of mass transfer from the less massive component to the more
massive one. The cyclic period variation of UY UMa may be interpreted
in terms of either the magnetic activity or the light time effect.
Description:
In order to construct the (O-C) diagram to analyze the period change
of UY UMa, we have performed a careful search for all available times
of light minima. A total of 76 times of light minima were collected
and listed in Table 2.
From the literatures and two well-known databases (i.e., the O-C
gateway (http://var.astro.cz/ocgate) and the Lichtenknecker database
of the BAV (http://www.bav-astro.de/LkDB/index.php)), we have
collected a total of 75 available times of light minima for EF Boo,
which are summarized in Table 3.
Objects:
-----------------------------------------------
RA (2000) DE Designation(s)
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13 44 36.83 +55 13 18.4 UY UMa = V* UY UMa
14 32 30.54 +50 49 40.7 EF Boo = V* EF Boo
-----------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 49 76 All compiled times of light minimum for the
contact binary UY UMa
table3.dat 49 75 All compiled times of light minimum for the
contact binary EF Boo
refs.dat 71 69 References
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Byte-by-byte Description of file: table2.dat table3.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian date
15- 16 A2 --- Type [I ] Type of minima
18- 23 F6.4 d e_HJD ?=- Error on HJD
25- 27 A3 --- Met Method
29- 36 F8.1 d Epoch Epoch
38- 45 F8.5 --- O-C Observed minus computed residual
47- 49 A3 --- Ref Reference, in refs,dat file
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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- 3 A3 --- Ref Reference code
5- 23 A19 --- BibCode BibCode
25- 44 A20 --- Aut Author's name
46- 71 A26 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 08-Nov-2017