J/AJ/148/96 Times of minimum light for IR Cas (Li+, 2014)
The first photometric analysis of the near contact binary IR Cas.
Li K., Hu S.-M., Guo D.-F., Jiang Y.-G., Gao D.-Y., Chen X.
<Astron. J., 148, 96 (2014)>
=2014AJ....148...96L 2014AJ....148...96L
ADC_Keywords: Binaries, eclipsing
Keywords: binaries: close - binaries: eclipsing - stars: individual: IR Cas
Abstract:
The first photometric analysis of IR Cas was carried out based on the
new observed BVRI light curves. The symmetric light curves and nearly
flat secondary minimum indicate that very precise photometric results
can be determined. We found that IR Cas is a near contact binary with
the primary component filling its Roche lobe. An analysis of the O-C
diagram based on all available times of minimum light reveals evidence
for a periodic change with a semi-amplitude of 0.0153days and a period
of 39.7yr superimposed on a secular decrease at a rate of
dp/dt=-1.28(±0.09)x10-7days/yr. The most reasonable explanation
for the periodic change is the light time-travel effect due to a third
body. The period decrease may be caused by mass transfer from the
primary component to the secondary. With the decreasing period, IR Cas
would eventually evolve into a contact system.
Description:
IR Cas was observed by using the 1.0m telescope at Weihai Observatory
of Shandong University (WHOT) on 2013 October 8 and 9, and 2013
November 4 and 7. WHOT is a classical Cassegrain telescope with a
focal ratio of f/8.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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23 06 52.37 +54 04 52.2 V* IR Cas = GSC 03998-02007 (P=0.680686)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 119 372 Times of minimum light for IR Cas
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AJ/144/37 : BVRI photometry of the eclipsing binary BS Vul (Zhu+, 2012)
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
15 A1 --- f_HJD [1] This minimum is discarded during the fitting
18- 20 A3 --- Meth Observational method used (1)
22 A1 --- Type Eclipse type (p=primary, s=secondary)
24- 31 F8.1 --- Epoch Epoch number
33- 39 F7.4 d O-C1 The (O-C)1 residual (2)
41- 47 F7.4 d O-C2 The (O-C)2 residual from the quadratic term
(equation (2) in the paper)
49- 55 F7.4 d Res Residual
57- 67 A11 --- Journal Journal name (4)
69- 72 I4 --- Vol ? Volume number
74- 76 I3 --- Page ? Page number
78- 96 A19 --- BibCode Bibliographic code
98-119 A22 --- Cat VizieR catalog
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Note (1): Detector code defined as follows:
pg = photographic plate;
vis = visual observation;
ccd = CCD detector;
pe = photoelectric detector.
Note (2): Computed from the following linear ephemeris,
Min.I=2446332.4510+0.680686E (Equation (1) in the paper).
Note (3): See Equation (2) in the paper.
Note (4): Journal code defined as follows:
PZ = Perem. Zvedy;
PSMO = Publications of the Sternberg Astronomical Institute/Observatory;
MVS = Mitt. Veranderliche Sterne
BBSAG = The group of eclipsing binary observers of the Swiss Astronomical
Society;
GCVS = General Catalogue of Variable Stars;
BAAVSS = The British Astronomical Association Variable Star Section;
BRNO = Brno Regional Network of Observers;
O-C Gateway = http://var.astro.cz/ocgate/
IBVS = Information Bulletin on Variable Stars;
AAVSO = American Association of Variable Star Observers;
VSOLJ = Variable Star Observers League in Japan;
OEJV = Open European Journal on Variable stars
JAAVSO = Journal of the American Association of Variable Star Observers.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 09-Dec-2014