J/other/NewA/41.17 Time of minima of BX Peg (Li+, 2015)
Four color light curves and period changes investigation of the
contact binary BX Peg.
Li K., Hu S., Guo D., Jiang Y., Gao D., Chen X.
<New Astron., 41, 17-21 (2015)>
=2015NewA...41...17L 2015NewA...41...17L (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing
Keywords: stars: binaries: close - stars: binaries: eclipsing -
stars: individual (BX Peg)
Abstract:
We presented BVRcIc light curves of BX Peg obtained by the Weihai
Observatory 1.0m telescope of Shandong University. The W-D code was
used to analyze the four color light curves, it is shown that BX Peg
is a W-subtype shallow contact binary with a fill-out factor of
f=14.6%. The asymmetric light curves were explained by a dark spot on
the less massive hot component. A total of 328 times of minimum light
were used to study the orbital period variation of BX Peg. We found
that the orbital period of BX Peg was continuous decrease with a rate
of dp/dt=-2.07x10-7d/yr superimposed on a cyclic oscillation
with a period of 57.8yr. The secular period decrease should be caused
by the angular momentum loss via magnetic stellar wind. The cyclic
modulation is very likely to be produced by the light travel time
effect due to a tertiary companion.
Description:
We monitored BX Peg using the Weihai Observatory 1.0-m telescope
(WHOT) of Shandong University on August 29th and September 9th, 2014.
WHOT is a classical Cassegrain telescope.
It has been about six years since the detailed study of the period
variation of BX Peg by Lee et al. (2009, Cat. J/PASP/121/1366). A lot
of times of minimum light have been obtained during these years. This
allows us to reanalyze the period change of BX Peg. By our new
determined times of minimum light and those collected from
literatures, a total of 328 times of minimum light which span about
88yr were used to analyze the period variation of BX Peg.
Objects:
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RA (2000) DE Designation(s)
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21 38 49.39 +26 41 34.2 BX Peg V* BX Peg
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 67 328 Times of minimum light for BX Peg
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See also:
J/PASP/121/1366 : BVR light curves of BX Peg (Lee+, 2009)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian date
14- 16 A3 --- Meth Method used (CCD, pe, pg or vis)
18 A1 --- Type [ps] Type of eclipse, primary or secondary
20- 27 F8.1 d E Epoch of minimum light
29- 35 F7.4 d O-C1 O-C determined by the linear ephemeris of
Eq. (1) of the paper
37- 43 F7.4 d O-C2 O-C which remove the quadratic term from
the (O-C)1
45- 51 F7.4 d Res Residual from full ephemeris of Eq. (2)
of the paper
53- 67 A15 --- Ref Reference (1)
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Note (1): The website of O-C Gateway is http://var.astro.cz/ocgate
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Jan-2017