J/AJ/164/202 Extremely Low Mass Ratio Contact Binaries I. 10 systems (Li+, 2022)
Extremely Low Mass Ratio Contact Binaries.
I. The First Photometric and Spectroscopic Investigations of Ten Systems.
Li K., Gao X., Liu X.-Y., Gao X., Li L.-Z., Chen Xu, Sun G.-Y.
<Astron. J., 164, 202 (2022)>
=2022AJ....164..202L 2022AJ....164..202L
ADC_Keywords: Binaries, eclipsing; Spectra, optical
Keywords: Close binary stars ; Eclipsing binary stars ; Contact binary
stars ; Mass ratio ; Stellar activity ; Stellar evolution
Abstract:
The photometric and spectroscopic investigations of ten contact
binaries were presented for the first time. It is discovered that the
mass ratios of all the ten targets are smaller than 0.15, they are
extremely low mass ratio contact binaries. Seven of them are deep
contact binaries, two are medium contact binaries, while only one is a
shallow contact system. Five of them show the O'Connell effect, and a
dark spot on one of the two components can lead to a good fit of the
asymmetric light curves. The orbital period studies of the ten
binaries reveal that they all exhibit long-term period changes, six of
them are increasing, while the others are shrinking. The LAMOST
spectra were analyzed by the spectral subtraction method, and all the
ten targets exhibit excess emissions in the Hα line, indicating
chromospheric activity. The evolutionary states of the two components
of the ten binaries were studied, and it is found that their
evolutionary states are identical to those of the other contact
binaries. Based on the study of the relation between orbital angular
momentum and total mass, we discovered the ten systems may be at the
late evolutionary stage of a contact binary. The initial masses of the
two components and the ages of them were obtained. By calculating the
instability parameters, we found that the ten contact binaries are
relatively stable at present.
Description:
4m-class telescopes were applied to observe the ten Extremely
low mass ratio contact binaries (ELMRCBs). The information of the four
meter-class telescopes is as follows.
The 60cm Ningbo Bureau of Education and Xinjiang Observatory Telescope
(NEXT). This telescope is equipped with an FLI PL23042 CCD, resulting
a field of view of 22x22'
The Tsinghua-NAOC 80cm Telescope (TNT). The PIXIS 1300B CCD was used
for this telescope, providing a field of view of 11.4x11.1".
The 85cm telescope at the Xinglong Station of National Astronomical
Observatories (XL85). This telescope used an Andor DZ936 CCD, and its
field of view is 32x32'.
The Weihai Observatory 1.0m telescope of Shandong University (WHOT.
The PIXIS 2048B CCD was equipped on this telescope, and the field of
view is 12x12'.
All the ten systems have been observed as part of the The Large sky
Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)
low-resolution spectroscopic survey. LAMOST is a 4m reflecting Schmidt
telescope with a 5deg field of view. It has 4000 fibers mounted on its
focal plane to make a very high spectral acquisition rate. The
spectral resolution of the low-resolution spectroscopic survey is
R∼1800 covering the wavelength range of about 3700-9000Å.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 103 10 Information of the 10 systems from ASAS-SN database
table6.dat 84 537 Eclipse times of ten targets
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See also:
II/366 : ASAS-SN catalog of variable stars (Jayasinghe+, 2018-2020)
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
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/MNRAS/373/1483 : W UMa type and CAB stars dynamical evolution (Eker+, 2006)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/A+A/494/209 : Pre-main sequence evolutionary tracks (Landin+, 2009)
J/other/RAA/11.924 : Atmospheric parameters for 771 stars (Wu+, 2011)
J/AJ/146/157 : Differential BVRI photometry of FI Boo (Christopoulou+, 2013)
J/MNRAS/430/2029 : Initial masses of WUMa type contact binaries (Yildiz+, 2013)
J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)
J/MNRAS/437/185 : W UMa-type contact binaries ages and masses (Yildiz, 2014)
J/AJ/157/207 : BVRcIc light curve observations for VZ Lib (Liao+, 2019)
J/ApJS/244/43 : Binary stars parameters LAMOST & Kepler obs. (Zhang+, 2019)
J/AJ/159/189 : Eclipse timings for 9 contact binaries (Li+, 2020)
J/AJ/162/13 : Parameters estimation for 173 eclipsing binaries (Li+, 2021)
J/AJ/161/221 : Photometry & spectroscopy of 4 binaries stars (Panchal+, 2021)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 28 A28 --- ASAS ASAS-SN Name
30- 36 A7 --- ID Identifier in this work
38- 63 A26 --- OName Other name
65- 73 F9.7 d Per [0.28/0.63] Period
75- 84 F10.5 d HJD [8812/9483] Heliocentric Julian Date; HJD-2450000
86- 92 F7.5 d e_HJD [0.0002/0.002] Error on HJD
94- 98 F5.2 mag Vmag [11.6/14.9] V-band magnitude
100-103 F4.2 mag Amp [0.26/0.39] Amplitude
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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- 28 A28 --- ASAS ASASSN-V name
30- 36 A7 --- ID Identifier used in this work
38- 49 F12.4 d BJD [2452749/2459483] Barycentric Julian date of
eclipse
51- 56 F6.4 d e_BJD [0/0.02] Uncertainty in BJD
58- 65 F8.1 --- Eclipse [-21145/1068] Eclipse number
67- 73 F7.4 --- O-C [-0.044/0.09] Observed - Calculated
75- 81 F7.4 --- Res [-0.013/0.06] Residuals
83- 84 I2 --- Ref [1/10] References(s) used (1)
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Note (1): References as follows:
1 = Catalina Sky Surveys, CSS, Drake+, 2009, J/ApJ/696/870
2 = Super Wide Angle Search for Planets, SuperWASP,
Butters+, 2010A&A...520L..10B 2010A&A...520L..10B
3 = All-Sky Automated Survey for SuperNovae, ASAS-SN,
Shappee+, 2014, J/ApJ/788/48, Jayasinghe+, 2018, II/366
4 = Transiting Exoplanet Survey Satellite, TESS,
Ricker+, 2015JATIS...1a4003R 2015JATIS...1a4003R
5 = 60cm Ningbo Bureau of Education and Xinjiang Observatory
Telescope (NEXT)
6 = Zwicky Transient Facility (ZTF) survey, Bellm+, 2019PASP..131a8002B 2019PASP..131a8002B,
Masci+, 2019PASP..131a8003M 2019PASP..131a8003M
7 = 85cm telescope at the Xinglong Station of National Astronomical
Observatories (XL85)
8 = Tsinghua-NAOC 80cm Telescope, TNT, Huang+, 2012RAA....12.1585H 2012RAA....12.1585H
9 = All Sky Automated Survey, ASAS, Pojmanski, 1997AcA....47..467P 1997AcA....47..467P
10 = Weihai Observatory 1.0m telescope of Shandong University, WHOT,
Hu+, 2014RAA....14..719H 2014RAA....14..719H
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 29-Nov-2022