J/AJ/152/120 BV photometry of V532 Mon (He+, 2016)
The first photometric investigation of the neglected W-UMa-type binary star V532
Monocerotis.
He J.-J., Qian S.-B., Soonthornthum B.
<Astron. J., 152, 120-120 (2016)>
=2016AJ....152..120H 2016AJ....152..120H (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Photometry, UBV
Keywords: binaries: close - binaries: eclipsing - stars: evolution -
stars: individual: V532 Mon
Abstract:
The first two sets of complete charge-coupled device light curves in
the B and V bands of the short-period binary system, V532 Mon, are
presented. The light curves are analyzed with spot models using the
Wilson-Devinney code. V532 Mon is found to be an A-subtype
intermediate-contact binary with a degree of contact factor of
f=47.1%(±2.7%), a mass ratio of q=0.2502(±0.0019), and a cool spot
on the primary component. The period changes of the system are
investigated by combining newly determined times of light minimum with
others published in the literature. We found that the general trend of
the observed-calculated (O-C) curve shows a downward parabolic
variation that corresponds to a long-term decrease in the orbital
period at a rate of dP/dt=-1.716(±0.002)*10-7dyr-1. The
long-term decrease of the orbital period can be explained by mass
transfer from the more-massive component to the less massive one. The
long-time period decrease, the intermediate-contact configuration, and
the astrophysical parameters of the binary system suggest that V532
Mon will evolve into high fill-out, extreme mass-ratio overcontact
binaries.
Description:
The observations of V532 Mon in the B and V bands were carried out on
2004 January 22, 26, and February 16 with the PI1024 TKB CCD
photometric system attached to the 1.0m reflecting telescope at the
Yunnan Observatories in China. The B and V color filter systems, which
are close to the standard Johnson UBV system, were used. The effective
field of view of the photometric system is 6.5*6.5 square arcmin at
the Cassegrain focus, and the size of each pixel is 0.38 arcsec. The
integration time for each image is 120s. PHOT (measure magnitudes for
a list of stars) from the aperture photometry package of IRAF was used
to reduce the observed images. We set the photometry aperture in the
reductions to 1.5 times FWHM. The photometric errors for the
individual observations were 0.002-0.009mag in the B band and
0.001-0.007mag in the V band. The standard deviations of the
measurements in the B and V bands were 0.010 and 0.005, respectively.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 51 3 Coordinates and color index of V532 Mon, the
comparison, and the check stars
table2.dat 14 128 CCD photometric data of V532 Mon in the B band
table3.dat 14 129 CCD photometric data of V532 Mon in the V band
table5.dat 90 79 (O-C) values of light minimum times for V532 Mon
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See also:
I/317 : The PPMXL Catalog (Roeser+ 2010)
V/119 : Catalogue of field contact binary stars (Pribulla+, 2003)
J/other/IBVS/5984 : Minima and maxima of 503 variables (Hubscher, 2011)
J/other/IBVS/5918 : Minima and maxima of 452 variables (Hubscher+, 2010)
J/other/IBVS/5874 : Minima and maxima of 299 variables (Hubscher+, 2009)
J/other/IBVS/5802 : Minima and maxima of 735 variables (Hubscher+, 2007)
J/AJ/131/2986 : Multiplicity of contact binaries (Pribulla+, 2006)
J/other/IBVS/5493 : 2003 CCD minima of eclipsing binaries (Nelson+, 2004)
J/other/IBVS/5296 : Extrema of pulsating stars (Agerer+, 2002)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 A2 --- f_Name Flag on Name (V=Variable, C=Comparison, CH=Check)
4- 11 A8 --- Name Star name
13- 14 I2 h RAh Hour of Right Ascension (J2000) (1)
16- 17 I2 min RAm Minute of Right Ascension (J2000) (1)
19- 24 F6.3 s RAs Second of Right Ascension (J2000) (1)
26 A1 --- DE- Sign of the Declination (1)
27- 28 I2 deg DEd Degree of Declination (J2000) (1)
30- 31 I2 arcmin DEm Arcminute of Declination (J2000) (1)
33- 37 F5.2 arcsec DEs Arcsecond of Declination (J2000) (1)
39- 44 F6.3 mag Jmag The J-band magnitude (1)
46- 51 F6.3 mag Hmag The H-band magnitude (1)
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Note (1): From the PPMXL Catalog (Roeser et al. 2010, Cat. I/317).
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Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 8 F8.5 d HJD [27/52.3] Heliocentric Julian Date (HJD-2453000)
10- 14 F5.3 mag Dmag [0.43/1.37] The differential magnitude (1)
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Note (1): In the sense of the variable minus the comparison star (HD293068). The
B and V color filter systems, which are close to the standard Johnson UBV
system, were used. The photometric errors for the individual observations
were 0.002-0.009mag in the B band and 0.001-0.007mag in the V band. The
standard deviations of the measurements in the B and V bands were 0.010 and
0.005, respectively.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d HJD Light minimum time in Heliocentric Julian Date
(HJD-2400000)
13 A1 --- Min [ps] Type of minimum (P=primary, or s=secondary)
15- 17 A3 --- Meth Detection method (pg=photographic and visual data,
or CCD=photoelectric and CCD observations)
19- 26 F8.1 --- E [-50858/7078] Eclipse number
28- 34 F7.4 --- O-C [-0.0688/0.04] The (O-C) value (observational
time-calculational time of the light minimum) (1)
36- 42 F7.4 --- Res [-0.0202/0.0305] Residual
44- 90 A47 --- Ref Reference
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Note (1): Calculated by Equation (1):
Min.I (HJD)=2453052.06475+0.4669795(days)*E.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 24-May-2017