J/AJ/149/62 BVR light curves of V508 Oph (Xiang+, 2015)
CCD photometric study and period investigation of V508 Oph.
Xiang F.-Y., Yu Y.-X., Xiao T.-Y.
<Astron. J., 149, 62 (2015)>
=2015AJ....149...62X 2015AJ....149...62X
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI ; Photometry, CCD
Keywords: binaries: eclipsing - binaries: general - stars: individual: V508 Oph
Abstract:
In this paper, new CCD photometric observations of V508 Oph obtained
in 2009 and 2010 at the Xinglong Observatory are presented. From the
new observations, six new times of minimum light were derived. The
light curves were analyzed by using the 2003 version of the
Wilson-Devinney program. It is found that the asymmetric light curves
can be modeled by a hot spot on the secondary component. The degree of
overcontact is 15.4%, implying that the system is a shallow-contact
binary. Combining the new times of minimum light with the
photoelectric and CCD data compiled from the database, we investigate
its orbital period. The results show that the orbital period may be
undergoing multiple changes: a long-term decrease at a rate of
dP/dt=-(1.502±0.063)x10-7days/year, and a small periodic variation
with a period of 24.27(±0.34) years. Since V508 Oph is an
overcontact system and both components are late-type stars, we discuss
the possible connection between the mass transfer, magnetic activity,
the third body, and the orbital period changes.
Description:
CCD photometric observations of the W UMa-type binary V508 Oph were
obtained from 2009 to 2010 with the PI1024 CCD photometric system
attached to the 0.6m reflecting telescope at the Xinglong
Observatory. The BVR passbands used are in the standard Johnson UBVRI
system.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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17 58 48.62 +13 29 46.3 V* V508 Oph = HIP 88028 (P=0.34479141)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 23 759 CCD photometric data of V508 Oph in the B band
table4.dat 23 805 CCD photometric data of V508 Oph in the V band
table5.dat 23 809 CCD photometric data of V508 Oph in the R band
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
J/AJ/146/35 : BVR light curves of DZ Psc (Yang+, 2013)
J/AJ/143/122 : VR light curves of CK Boo (Yang+, 2012)
Byte-by-byte Description of file: table[345].dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 d HJD Heliocentric Julian Date (HJD-2450000)
11- 16 F6.4 --- Phase Phase (1)
18- 23 F6.3 mag Dmag The Δ magnitude
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Note (1): Calculated by Equation (1):
Min.I=HJD2455383.1889±0.0008+0.34479141±0.00000005*Edays.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 24-Feb-2015