J/ApJ/901/169 Photometric obs. & LAMOST sp. of 4 W UMa binaries (Lu+, 2020)
Magnetic activity and period variation studies of the four W Uma-type eclipsing
binaries: UV Lyn, V781 Tau, NSVS 4484038, and 2MASS J15471055+5302107.
Lu H.-P., Zhang L.-Y., Michel R., Han X.L.
<Astrophys. J., 901, 169 (2020)>
=2020ApJ...901..169L 2020ApJ...901..169L
ADC_Keywords: Binaries, eclipsing; Photometry, UBVRI; Spectroscopy;
Abundances, [Fe/H]; References
Keywords: Starspots ; Eclipsing binary stars ; Contact binary stars
Abstract:
We present new photometric data and LAMOST spectra for the W UMa
binaries UV Lyn, V781 Tau, NSVS 4484038, and 2MASS J15471055+5302107.
The orbital and starspot parameters are obtained using the
Wilson-Devinney program. Comparing the starspot parameters at
different times, there are magnetic activities in these four binaries.
The orbital period of UV Lyn is increasing at a rate of
dP/dt=+8.9(5)x10-8d/yr, which maybe due to mass transfer from the
less massive component to the more massive component
(dM1/dt=-6.4x10-8M☉/yr). The period variation of
2MASSJ15471055+5302107 is also increasing at a rate of
6.0(4)x10-7d/yr, which can be explained by mass transfer from the
less massive component to the more massive component
(dM1/dt=-2.8x10-7M☉/yr). The period variation of V781 Tau
presents the downward parabola superimposed the cyclic oscillation.
The period of V781 Tau is decreasing (dP/dt=-3.2(4)x10-8d/yr), which
can be explained by mass transfer from the more massive component to
the less massive component (dM2/dt=-2.2x10-8M☉/yr). The cyclic
oscillation may be due to the magnetic activity with a period of
30.8(5)yr rather than a third body. The period variation of
NSVS4484038 also shows the cyclic oscillation, which could be
explained by the magnetic activity with 10.8(1)yr or a black hole
candidate. Interestingly, there is a depth variation between the light
minimum times of NSVS 4484038, which may also be caused by stellar
magnetic activity.
Description:
In this study, we used four photometric telescopes to perform
multiband photometry on our four W Uma-type binary systems: the 1m RCC
reflecting telescope at Yunnan Observatory, the 84cm f/15
Ritchey-Chretien telescope at OAN-SPM Baja California, Mexico, the
60cm reflecting telescope at Xinglong Station of the National
Astronomical Observatories of China (NAOC) and the SARA 91.4cm
telescope at the Kitt Peak National Observatory in Arizona.
For UV Lyn, we performed two full-phase photometric observations. The
first time was on 2014 November 15 and 16. The second time was on 2019
January 17 and 18.
For V781 Tau, we performed BVRI-band photometric observations on 2015
January 20 using the 1m RCC reflecting telescope.
For NSVS 4484038, we used the 84cm f/15 Ritchey-Chretien telescope to
perform two photometric observations, one on 2016 October 22 and
November 5, using BVR filters, and the other on 2017 November 6, using
BVRI filters. In addition, we also used the SARA 91.4cm telescope to
perform the BVRI multiband photometric observation of NSVS 4484038 on
2019 December 2.
For 2MASS J15471055+5302107, we performed two BVR-band photometric
observations with the 84cm f/15 Ritchey-Chretien telescope. The first
photometric observations were on 2016 April 24 and 2018 April 25.
See Section 2.1. for further explanations.
By cross-matching our four eclipsing binaries with LAMOST DR5, we
obtained the LAMOST spectra with a resolution R∼1800 of UV Lyn,
NSVS4484038, and 2MASS J15471055+5302107. LAMOST conducted two
observations on UV Lyn, one on 2013 November 19 and the other on
2014 January 21 and an observation of NSVS 4484038 and
2MASSJ15471055+5302107, which were observed on 2012 June 17 and
2016 February 19, respectively. See Section 2.2.
Combining the light minimum times of the four binary systems collected
from the O-C website (http://var2.astro.cz/EN/) and the literature and
the light minimum times we observed, we systematically analyzed the
period variations of the four binary stars. See Section 3.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 131 3431 Photometric data of UV Lyn, V781 Tau, NSVS4484038
and 2MASS J15471055+5302107
table4.dat 125 5 LAMOST spectral parameters of UV Lyn, NSVS4484038,
and 2MASS J15471055+5302107
table5.dat 98 594 Light minimum times fitting parameters
refs.dat 70 93 References
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See also:
V/146 : LAMOST DR1 catalogs (Luo+, 2015)
J/AJ/106/2096 : Limb-darkening coefficients in binaries (Van Hamme 1993)
J/A+A/336/920 : HD 163151: a new W UMa type system (Rodriguez+ 1998)
J/other/IBVS/5438 : 162-nd list of minima of EBs (Diethelm, 2003)
J/other/IBVS/5493 : 2003 CCD minima of eclipsing binaries (Nelson+, 2004)
J/AJ/128/426 : Subdwarfs in the SDSS (West+, 2004)
J/A+A/429/309 : HR 1099 radial velocities (Frasca+, 2005)
J/other/IBVS/5592 : Eclipsing binary stars photoelectric minima (Krajci+, 2005)
J/MNRAS/372/1117 : SuperWASP exoplanetary transit survey (Christian+, 2006)
J/other/IBVS/5731 : Minima and maxima of 816 variables (Hubscher+, 2006)
J/A+A/452/959 : BV light curve of V781 Tau (Kallrath+, 2006)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/AJ/134/2398 : Stellar SEDs in SDSS and 2MASS filters (Covey+, 2007)
J/other/IBVS/5761 : Minima and maxima of 389 variables (Hubscher+, 2007)
J/A+A/467/785 : SuperWASP/ROSAT periodic variable stars (Norton+, 2007)
J/AJ/136/1089 : UBVRI light curves of TU Boo (Coughlin+, 2008)
J/AJ/138/466 : NSVS variables automated classification (Hoffman+, 2009)
J/other/IBVS/5889 : Minima and maxima of 380 variables (Hubscher+, 2009)
J/AJ/142/99 : BVRI observations of TZ Boo (Christopoulou+, 2011)
J/other/IBVS/5984 : Minima and maxima of 503 variables (Hubscher, 2011)
J/other/IBVS/5959 : Minima and maxima of 436 variables (Huebscher+, 2011)
J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)
J/AJ/146/79 : Differential BVRI light curves of EP And (Liao+, 2013)
J/A+A/549/A86 : Period change for 143 SuperWASP EBs (Lohr+, 2013)
J/AJ/147/66 : LCs of Algol-type binaries. VII. V404 And (Zhang+, 2014)
J/MNRAS/448/2890 : Observation of 6 NSVS eclipsing binaries (Dimitrov+, 2015)
J/AJ/149/90 : UBVRI light curves of GSC 3208-1986 (Samec+, 2015)
J/MNRAS/455/4136 : Kepler triples (Borkovits+, 2016)
J/AJ/152/120 : BV photometry of V532 Mon (He+, 2016)
J/AJ/158/186 : 12 totally eclipsing W UMa stars phot. (Kjurkchieva+, 2019)
J/AJ/157/111 : Study of 3 early-type contact twin binaries (Yang+, 2019)
http://var2.astro.cz/EN/ : Access to O-C gateway database
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Star name
25- 37 F13.5 d HJD-B ? Heliocentric Julian Date of B band observation
39- 43 F5.3 --- Phase-B [0.001/1]? Orbital phase of B band observation
45- 50 F6.3 mag DelBmag [-2.71/0.62]? Different Magnitude in B filters
52- 64 F13.5 d HJD-V ? Heliocentric Julian Date of V band observation
66- 70 F5.3 --- Phase-V [0/1]? Orbital phase of V band observation
72- 77 F6.3 mag DelVmag [-2.8/0.37]? Different Magnitude in V filters
79- 91 F13.5 d HJD-R [2457007.18/2458875.1] Heliocentric Julian Date
of R band observation
93- 97 F5.3 --- Phase-R [0/1] Orbital phase of R band observation
99-104 F6.3 mag DelRmag [-2.9/0.15] Different Magnitude in R filters
106-118 F13.5 d HJD-I ? Heliocentric Julian Date of I band observation
120-124 F5.3 --- Phase-I ? Orbital phase of I band observation
126-131 F6.3 mag DelImag [-2.95/-0.11]? Different Magnitude in I filters
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Star name (1)
25 A1 --- n_Name [a] Note on Name (2)
27- 32 A6 --- --- [LAMOST]
34- 52 A19 --- LAMOST LAMOST identifier (JHHMMSS.ss+DDMMSS.s)
54- 66 F13.5 d HJD ? Heliocentric Julian Date
68- 73 F6.2 --- S/Nr [30.69/395.71]? Signal to noise ratio in r-band
75- 77 A3 --- SpT Spectral type
79- 85 F7.2 s Exp [1200/2700]? Exposure time
87- 90 I4 K Teff [5625/6664]? Effective temperature
92- 94 I3 K e_Teff [17/154]? Teff uncertainty
96- 99 F4.2 [cm/s2] logg [3.99/4.25]? Log of surface gravity
101-104 F4.2 [cm/s2] e_logg [0.03/0.2]? Logg uncertainty
106-109 F4.2 [Sun] [Fe/H] [0.05/0.4]? Log of Fe/H abundance
111-114 F4.2 [Sun] e_[Fe/H] [0.01/0.1]? Fe/H uncertainty
116-120 F5.2 0.1nm EWHa [-1.6/-0.34]? Hα equivalent width in
Angstrom units
122-125 F4.2 0.1nm e_EWHa [0.02/2]? EWHa uncertainty
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Note (1): V781 Tau has been added by CDS in this table for technical purposes.
Note (2): Flag as follows:
a = NSVS 4484038 misidentified with LAMOST J055430.99+442344.2 which
is associated to TYC 2924-2003-1; note added by CDS.
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Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Name Star name
25- 37 F13.5 d HJD [2415021.9/2458875.1] Heliocentric Julian Date
39- 45 F7.5 d e_HJD [4e-05/0.01]? Uncertainty in HJD
47- 54 F8.1 --- Epoch [-60845.5/43931.5] Epoch number
56- 58 A3 --- Meth Observational method
60- 62 A3 --- Type Eclipse type ("Pri"=335 occurrences or
"Sec"=259 occurrences)
64- 65 I2 --- Weight [1/10] Weight
67- 74 F8.5 --- (O-C)I [-0.044/0.33] Residual of fit
76- 83 F8.5 --- (O-C)II [-0.11/0.18] Other residual (1)
85- 92 F8.5 --- (O-C)Sine [-0.05/0.05]? Residual of sine fit
94- 98 A5 --- Ref Reference(s) (see refs.dat file)
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Note (1): For UV Lyn and 2MASS J15471055+5302107 this is the residual of the
parabolic fit. For V781 Tau and NSVS 4484038 this is the residual of
the third body fit.
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Byte-by-byte Description of file: refs.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode of the reference
24- 45 A22 --- Auth First author's name(s)
47- 70 A24 --- Comm Comment
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Acknowledgements:
Hong-peng, Lu [hplu at_ pku.edu.cn]
History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 17-Jan-2022