J/AJ/137/3181 HW Vir differential VR light curves (Lee+, 2009)
The sdB+M eclipsing system HW Virginis and its circumbinary planets.
Lee J.W., Kim S.-L., Kim C.-H., Koch R.H., Lee C.-U., Kim H.-I., Park J.-H.
<Astron. J., 137, 3181-3190 (2009)>
=2009AJ....137.3181L 2009AJ....137.3181L
ADC_Keywords: Binaries, eclipsing ; Photometry, CCD ; Photometry, UBV
Keywords: binaries: close - binaries: eclipsing - planetary systems -
stars: individual (HW Virginis)
Abstract:
For the very short period subdwarf B eclipsing binary HW Vir, we
present new CCD photometry made from 2000 through 2008. In order to
obtain consistency of the binary parameters, our new light curves,
showing sharp eclipses and a striking reflection effect, were analyzed
simultaneously with previously published radial velocity data. The
secondary star parameters of M2=0.14M☉, R2=0.18R☉, and
T2=3084K are consistent with those of an M6-7 main-sequence star. A
credibility issue regarding bolometric corrections is emphasized. More
than 250 times of minimum light, including our 41 timings and spanning
more than 24yr, were used for a period study. From a detailed analysis
of the O-C diagram, it emerged that the orbital period of HW Vir has
varied as a combination of a downward-opening parabola and two
sinusoidal variations, with cycle lengths of P3=15.8yr and
P4=9.1yr and semiamplitudes of K3=77s and K4=23s, respectively.
The continuous period decrease with a rate of -8.28x10-9d/yr may be
produced by angular momentum loss due to magnetic stellar wind braking
but not by gravitational radiation.
Description:
New CCD photometric observations of HW Vir were obtained between
2000 and 2008, except for 2001 and 2006, using the 61cm reflector
at Sobaeksan Optical Astronomy Observatory (SOAO) in Korea.
Objects:
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RA (2000) DE Designation(s)
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12 44 20.2 -08 40 17 HW Vir = BD-07 3477
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 1687 CCD photometric observations of HW Vir
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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 HJDV Heliocentric Julian Date of V band observation
15- 20 F6.3 mag DVmag Differential V band magnitude
22- 34 F13.5 d HJDR ? Heliocentric Julian Date of R band observation
36- 41 F6.3 mag DRmag ? Differential R band magnitude
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 26-Aug-2011