J/other/NewA/37.48 ZZ Cyg times of minima (Yang+, 2015)
A period study and revised photometric model for the eclipsing binary ZZ Cyg.
Yang Y., Zhang L., Dai H., Li H.
<New Astron., 37, 48-51 (2015)>
=2015NewA...37...48Y 2015NewA...37...48Y (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry
Keywords: stars: binary: close - binaries: eclipsing -
stars: individuals (ZZ Cyg)
Abstract:
We present new photometry of the eclipsing binary ZZ Cyg. From all
accumulated eclipsing times, we constructed the (O-C) curve, which
can be described by a downward parabola with a possible light-time
orbit. The period decrease rate is source dP/dt=-5.73(±0.18)d/yr.
The modulated period, semi-amplitude and eccentricity for the
light-time orbit are Pmod=71.4(±1.1)yr, A=0.0071(±0.0005)day and
e=0.420(±0.053), respectively. After removing effects of the
magnetic activity, this kind of cyclic oscillation may be attributed
to light-time effect via an additional companion. By using the W-D
code, the photometric model was updated, which identified that ZZ Cyg
is a near-contact binary. We find that a hot spot may occur on the
primary that explains the asymmetric light curve. The secular period
decrease may possibly cause the fill-out factor of the primary to
increase. Finally it will finally fill its Roche lobe. This kind of
binary, ZZ Cyg, may evolve into contact binary star.
Description:
CCD photometry of ZZ Cyg was carried out on 2009 October and 2013 July
and August, with the 60-cm telescope and the 85-cm telescope at the
Xinglong station (XLs) of National Astronomical Observatories of China
(NAOC). This telescope was equipped with the standard Johnson-Cousins
UBVRI filters. The data reduction was performed by using the IMRED and
APPHOT packages in IRAF in a standard mode.
Objects:
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RA (2000) DE Designation(s)
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20 23 52.91 +46 55 14.4 ZZ Cyg = V* ZZ Cyg
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 44 702 All compiled light minimum times of ZZ Cyg
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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- 21 F8.1 --- Epoch [-47692/18349.5] Epoch (cycle)
23- 25 A3 --- Method Observational method used: vi=visual,
pg=photographic, pe=photoeletric, or CCD
27- 28 A2 --- Min [I II] Minimum type
30- 36 F7.4 d (O-C)1 [-0.06/0.03] Eclipse time residual of the
linear fit
38- 44 F7.4 d (O-C)2 [-0.03/0.03] Eclipse time residual of the
parabolic fit
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Jul-2015