J/AJ/150/9 VRI light curves of GSC 1537-1557 (Xiang+, 2015)
First photometric investigation of the solar-type contact binary GSC 1537-1557.
Xiang F.-Y., Xiao T.-Y., Zhang B., Shi X.-D.
<Astron. J., 150, 9 (2015)>
=2015AJ....150....9X 2015AJ....150....9X
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: close - binaries: eclipsing -
stars: individual: GSC 1537-1557
Abstract:
By analyzing Rc and Iclight curves of the short-period solar-type
eclipsing binary GSC 1537-1557 we discovered that it is a shallow
contact binary with a degree of contact factor of f=(8.1±1.79)%.
Photometric solutions reveal that GSC 1537-1557 is a W-type system
with a mass ratio of q=M2/M1=2.645 where the less massive
component (the primary star) is about 110K hotter than the more
massive one (the secondary star). The asymmetry and variation of the
light curves were explained as the activity of spots on the solar-type
component stars. By investigating all of the available times of light
minima, we found that the observed-calculated (O-C) curve shows a
cyclic variation with a small amplitude of 0.00335days and a period of
8.1years. The small-amplitude cyclic change in the O -C curve was
analyzed for the light-travel time effect via the presence of an
extremely cool stellar companion. The mass of the third body was
determined to be M3sini'=(0.19±0.01)M☉ when
M1+M2=1.31M☉ is adopted for GSC 1537-1557. The semimajor
axis of the outer obit is a'sini'=(4.58±0.33)AU.
Description:
GSC1537-1557 was monitored with the 60cm reflecting telescope at
Yunnan Observatories (YNOs) on 2011 February 21, 23, 25, 27, April 2,
June 3, and 2012 May 18, and 2013, March 16. It was equipped with a
Cassegrain-focus multicolor CCD photometer where an Andor DW436 2 K
CCD camera was used. During the observations, the wide-band
Johnson-Cousins BVIcRc filters attached to this Cassegrain
telescope were applied. CCD photometric light curves of GSC1537-1557
were obtained in 2011 February with the 60cm telescope, and the
observations are listed in Tables 4 and 5. During the observations,
Rc and Ic filters were used.
GSC1537-1557 was also observed by using the 85cm reflecting telescope
at the Xinglong Observational Station of the National Astronomical
Observatory (NAO) on 2013 March 7 and the 1.0m reflecting telescope at
YNOs on 2014 October 5. The 1.0m telescope at YNOs was equipped with
the same CCD photometric system as the one at the 60cm telescope,
while the 85cm telescope was equipped with a primary-focus multicolor
CCD photometer where a PI1024 BFT (Back-illuminated and
Frame-Transfer) camera was used. The observations obtained in 2013
using the 85cm telescope in V, Rc, and Ic bands are listed in
Table8.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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17 20 21.49 +16 30 53.3 GSC 1537-1557 = ROTSE1 J172021.58+163051.9 (P=0.31827)
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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 15 New times of light minimum for GSC 1537-1557
table2.dat 94 19 All available times of light minimum for GSC 1537-1557
table4.dat 24 454 *CCD photometric data of GSC 1537-1557 in Rc band
table5.dat 24 272 *CCD photometric data of GSC 1537-1557 in Ic band
table8.dat 29 204 *CCD photometric data of GSC 1537-1557 in V band
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Note on table4.dat, table5.dat: Obtained with the 60cm telescope at
Yunnan Observatory (YNAO) in 2011 February.
Note on table8.dat: Obtained with the 85cm telescope at at the Xinglong
Observational Station of the National Astronomical Observatory (NAO) on
2013-03-07, This table also contains the Rc and Ic photometric data
from the same telescope and era.
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/other/IBVS/5543 : 163-nd list of eclipsing binaries minima (Diethelm+, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
15- 21 F7.5 d e_HJD Error in HJD
23- 29 F7.1 --- E [6290/10443] Epoch (cycle number)
31- 34 A4 --- Flt Filter used in the observation
(Johnson-Cousins V, Rc, Ic) (1)
36- 39 A4 --- Tel Telescope (60cm, 85cm, or 1.0m) (2)
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Note (1): "N" means no filter.
Note (2): The three telescopes used are defined as below:
60cm = The 60cm reflecting telescope at Yunnan Observatories (YNOs);
85cm = The 85cm reflecting telescope at the Xinglong Observational Station of
the National Astronomical Observatory (NAO);
1.0m = The 1.0m reflecting telescope at YNOs.
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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- 12 F12.4 d HJD Heliocentric Julian Date
14- 19 F6.4 d e_HJD Error in HJD
21- 23 A3 --- Meth [CCD] Method
25- 31 F7.1 --- E [-2699/10443] Epoch (cycle number)
33- 39 F7.4 d O-C2 [-0.005/0.010] The (O-C)1 value from Eq.(2)
41- 47 F7.4 d O-C3 [-0.004/0.003] The (O-C)2 value from Eq.(3)
49- 55 F7.4 d Res [-0.0011/0.0012] Residual
57- 94 A38 --- Ref Reference
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Note (2): Min.I(HJD) = 2453612.4616+0.318275(days)*E.
Note (3): Min.I(HJD) = 2453612.46246 + 0.31827564*E
+ 0.00335*sin(0.0390*E+335.9) [sine argument in °]
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Byte-by-byte Description of file: table[45].dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 d HJD Heliocentric Julian Date (HJD-2400000)
12- 17 F6.4 --- Phase [0/1] Phase (G1)
19- 24 F6.3 mag Dmag [-0.396/0.326] Differential magnitude
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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- 4 A4 --- Flt Filter used in the observation
(Johnson-Cousins V, Rc, Ic)
6- 15 F10.4 d HJD Heliocentric Julian Date (HJD-2400000)
17- 22 F6.4 --- Phase [0/1] Phase (G1)
24- 29 F6.3 mag Dmag [-0.371/0.457] Differential magnitude in Filter
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Global notes:
Note (G1): The phases are computed by using the ephemeris in Eq. (4):
Min. I(HJD)=2455618.39155+0.31827564(days)*E.
History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 14-Sep-2015