J/AJ/159/189 Eclipse timings for 9 contact binaries (Li+, 2020)
The first light curve modeling and orbital period change investigation of nine
contact binaries around the short-period cutoff.
Li K., Kim C.-H., Xia Q.-Q., Michel R., Hu S.-M., Gao X., Guo D.-F., Chen Xu
<Astron. J., 159, 189 (2020)>
=2020AJ....159..189L 2020AJ....159..189L
ADC_Keywords: Stars, double and multiple; Optical; Stars, diameters;
Stars, masses
Keywords: Close binary stars ; Eclipsing binary stars ; Stellar evolution
Abstract:
In this paper, we present the first light curve synthesis and orbital
period change analysis of nine contact binaries around the
short-period limit. It is found that all these systems are W-subtype
contact binaries. One of them is a medium contact system while the
others are shallow contact ones. Four of them manifest obvious
O'Connell effect explained by a dark spot or hot spot on one of the
component stars. Third light was detected in three systems. By
investigating orbital period variations, we found that four of the
targets display a secular period decrease while the others exhibit a
long-term period increase. The secular period decrease is more likely
caused by angular-momentum loss while the long-term period increase is
due to mass transfer from the less massive component to the more
massive one. Based on the statistic of 19 ultrashort-period contact
binaries with known orbital period changes, we found that seven of
them display long-term decrease (three of them also exhibit cyclic
variations), ten of them manifest long-term increase while two of them
only show cyclic variation, and that most of them are shallow contact
binaries supporting the long timescale angular-momentum loss theory
suggested by Stepien. For the three deep contact systems, we found
that they are probably triple systems. The tertiary companion plays an
essential role during their formation and evolution.
Description:
The observations of these ultrashort-period contact binaries (USPCBs)
were carried out with five meter-class telescopes from 2016 to 2019.
- The Weihai Observatory 1.0m telescope of Shandong University (WHOT)
- The 85cm telescope at the Xinglong Station of National Astronomical
Observatories (NAOs85cm) in China
- The 60cm Ningbo Bureau of Education and Xinjiang Observatory
Telescope (NEXT)
- The 84cm and 2.12m telescopes of the San Pedro Martir Observatory
(SPM84cm and SPM2.12m).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 98 9 Information of the studied stars
table6.dat 55 123 Eclipse timings for the nine stars
table8.dat 53 9 Absolute parameters of the stars
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
J/ApJ/629/1055 : Evolution of close binary systems (Yakut+, 2005)
J/AJ/134/2398 : Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)
J/AJ/137/236 : CC Com and BV Dra light curves (Yang+, 2009)
J/MNRAS/405/1930 : Period changes of EA-, EB- & EW-types binaries (Liao+, 2010)
J/other/JAVSO/38.183 : Time of minima of eclipsing binaries (Samolyk+, 2010)
J/A+A/528/A90 : SuperWASP short period eclipsing binaries (Norton+, 2011)
J/AcA/62/97 : Times of minima for 13 eclipsing binaries (Zasche, 2012)
J/AJ/145/100 : Differential BVR light curves of EP And (Lee+, 2013)
J/A+A/549/A86 : Period change 143 SuperWASP eclipsing binaries (Lohr+, 2013)
J/A+A/558/A71 : Times of minima for 1SWASP J234401.81-212229.1 (Lohr+, 2013)
J/AJ/146/58 : Eclipse timings for NGC 6819-259 (Jeffries+, 2013)
J/AJ/146/101 : LINEAR. III. Catalog of periodic variables (Palaversa+,2013)
J/ApJS/208/9 : Intrinsic colors & temperatures of PMS stars (Pecaut+, 2013)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/AJ/150/1 : Eclipse timings of 27 eclipsing binaries (Hong+, 2015)
J/AJ/157/207 : BVRcIc light curve observations for VZ Lib (Liao+, 2019)
http://wasp.cerit-sc.cz/form : SuperWASP data homepage
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Name Eclipsing binary name
28 A1 --- f_Name [a] Flag on Name (1)
30- 36 A7 --- ID Identification as used in this article
38- 39 I2 h RAh [0/22] Hour of right ascension (J2000)
41- 42 I2 min RAm Minute of right ascension (J2000)
44- 48 F5.2 s RAs Second of right ascension (J2000)
50 A1 --- DE- [+] Sign of declination (J2000)
52- 53 I2 deg DEd [1/57] Degree of declination (J2000)
55- 56 I2 arcmin DEm Arcminute of declination (J2000)
58- 61 F4.1 arcsec DEs Arcsecond of declination (J2000)
63- 70 F8.6 d Per [0.19/0.23] Period
72- 81 F10.5 d HJD [7675/8542] Heliocentric Julian Date; JD-2450000
83- 87 F5.2 mag Vmag [14.06/16.27] Visual magnitude
89- 92 F4.2 --- Ampl [0.21/0.68] Amplitude
94 A1 --- f_Ampl [b] Flag on Ampl (1)
96- 98 A3 --- Ref References (2)
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Note (1): Flags as follows:
a = The coordinates of this target were determined by Lohr+, 2013,
2013A&A...549A..86L 2013A&A...549A..86L but when we processed the observational data, we
found that the position of the variable star is
α2000.0=16h18min57.86s, δ2000.0=26deg13'38.5". The
short name was changed to J161857, and the corrected coordinates are
shown in the third and forth columns of this table.
b = The variability amplitude of this star was roughly determined with
the public data of SuperWASP (http://wasp.cerit-sc.cz/form).
Note (2): References as follows:
1 = Norton+, 2011, J/A+A/528/A90
2 = Lohr+, 2013, J/A+A/549/A86
3 = Drake+, 2014, J/ApJS/213/9
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- ID Star identification
9- 18 F10.5 d HJD [1491/8542] Heliocentric Julian Date; JD-2450000
20- 26 F7.5 d e_HJD [0.0001/0.003] Error on HJD
28- 35 F8.1 --- E [-29027/2590] Eclipsing time (1)
37- 44 F8.5 d O-C [-0.04/0.06] Computed O-C value
46- 53 F8.5 d Res [-0.02/0.008] Residual
55 I1 --- Ref [1/5] Reference used (2)
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Note (1): HJD=HJD0+PxE with HJD0 the reference time for each part and P the
orbital period.
Note (2): References as follows:
1 = Shappee+, 2014, J/ApJ/788/48 and Jayasinghe+, 2018MNRAS.477.3145J 2018MNRAS.477.3145J
2 = This work
3 = Drake, 2014 J/ApJS/213/9
4 = Wozniak+, 2004AJ....127.2436W 2004AJ....127.2436W
5 = Palaversa+, 2013, J/AJ/146/101
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- ID System identification
9- 12 F4.2 Msun Mass1 [0.13/0.68] Primary star mass
14- 17 F4.2 Msun Mass2 [0.4/0.79] Secondary star mass
19- 22 F4.2 Rsun a [1.26/1.66] Semi major axis
24- 27 F4.2 Rsun Rad1 [0.37/0.69] Primary star radius
29- 32 F4.2 Rsun Rad2 [0.54/0.77] Secondary star radius
34- 37 F4.2 Lsun Lum1 [0.04/0.23] Primary star luminosity
39- 42 F4.2 Lsun Lum2 [0.08/0.23] Secondary star luminosity
44- 48 F5.2 10-1Msun/yr dM1/dt [-8.56/1.8] Mass loss of primary star
50- 53 F4.2 10-1Msun/yr e_dM1/dt [0.08/0.92] Error on dM1/dt
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History:
From electronic version of the journal
(End) Prepared by Coralie Fix [CDS], 23-Sep-2020