J/other/NewA/35.48 Time minima of EP Aur (Li+, 2015)
A comprehensive photometric study of the eclipsing binary EP Aurigae.
Li H.-L., Wei J.-Y., Yang Y.-G., Li K., Zhang X.-B.
<New Astron., 35, 48-52 (2015)>
=2015NewA...35...48L 2015NewA...35...48L
ADC_Keywords: Binaries, eclipsing
Keywords: binaries: close - binaries: eclipsing - stars: individual (EP Aur)
Abstract:
We present new observations for the eclipsing binary EP Aurigae, which
were performed by using three small telescopes in China from 2003
December to 2014 January. With the updated 2003 version of the
Wilson-Devinney code, the photometric elements were deduced from
three sets of light curves. Based on all available eclipsing times,
the orbital period changes were investigated. It is discovered that
the (O-C) curve may show an existence of light-time effect due to an
unseen third body, which was weakly identified by the photometric
solution. The modulated period and amplitude of the cyclic variation
are P3=71.2(±8.0)yr and A=0.0101(±0.0008)day, respectively. In
the co-planar orbit with the binary system, the mass of the third body
is M3=0.18(±0.02)M☉. The photometric results imply that EP
Aur is an Algol-type binary with a mass ratio of q=0.831(±0.004).
Its primary component almost fills its Roche lobe. Therefore, EP Aur
may consist of a normal main-sequence star and a cool Roche-lobe
filling subgiant, which may be undergoing rapid mass transfer.
Description:
From 2003 December to 2014 January, the photometry of EP Aur was
performed by using the 60-cm telescope and the 85-cm telescope at the
Xinglong station (XLs) of National Astronomical Observatories of China
(NAOC), and the 1.0-m telescope at the Weihai Observatory (WHO) of
Shandong University. The three telescopes were equipped with standard
Johnson-Cousins UBVRcIc systems. All observed images were reduced by
using the IMREDIMRED and APPHOTAPPHOT packages in IRAF in a standard
fashion.
The multi-color photometry of EP Aur was carried out on 2013 December
1, 2, 3, and 5, 2009 January 3, 4 and 5 using the 60-cm telescope at
XLs. TYC 2420-434-1 and TYC 2420-193-1 were taken as the comparison
and check stars respectively.
Objects:
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RA (2000) DE Designation(s)
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06 11 32.12 +31 28 52.5 EP Aur = V* EP Aur
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 47 139 All compiled light minimum times for EP Aur
refs.dat 118 42 References
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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 d Ep [-37116/14272] Epoch (cycle)
23- 25 A3 --- Meth Method: vi=visual, pg=photographic,
pe=photoelectric, or CCD
27- 28 A2 --- Min [I II] Type of minimum
30- 36 F7.4 d (O-C)1 [-0.02/0.04] This paper residual
38- 44 F7.4 d (O-C)2 [-0.021/0.03] Other paper residual
46- 47 I2 --- r_(O-C)2 [1/42] Reference for (O-C)2, in refs.dat file
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference number
4- 22 A19 --- BibCode BibCode
24- 40 A17 --- Aut Author's name
42-118 A77 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 02-Jul-2015