J/AJ/149/90 UBVRI light curves of GSC 3208-1986 (Samec+, 2015)
UBVRI analysis of the totally eclipsing extreme mass ratio W UMa binary,
GSC 3208 1986.
Samec R.G., Kring J.D., Robb R., Van Hamme W., Faulkner D.R.
<Astron. J., 149, 90 (2015)>
=2015AJ....149...90S 2015AJ....149...90S
ADC_Keywords: Binaries, eclipsing ; Photometry, UBVRI
Keywords: binaries: close - binaries: eclipsing - stars: evolution -
stars: individual: GSC 3208 1986
Abstract:
GSC 3208 1986 is an NSVS and TYCHO binary, first observed from 1999 to
2000. It is a W UMa binary with a period of 0.405days. The present
observations were taken in 2012 September and are of high precision,
averaging a standard deviation of better than 5mmag. The amplitude of
the light curve is very nearly 0.5mag yet it undergoes total eclipses.
Dominion Astrophysical Observatory spectra give an F3V type (T∼6900K)
for the system, the earliest of the extreme mass ratio W UMa binaries.
The linear period determination of 0.4045672days was calculated with
the two sets of epochs available. An early NSVS light curve reveals
that the period has been smoothly decreasing over its past 12000
orbits. The binary may be undergoing sinusoidal oscillations due to
the presence of a third body, possibly with a period of 23±3years.
The high inclination of 85° results in a long duration secondary
total eclipse, lasting some 49.5minutes. Findings indicate that GSC
3208 1986 is an immaculate extreme mass ratio, q(m2/m1)=0.24,
A-type W UMa binary.
Description:
The GSC 3208 1986 system was observed as a part of our
student/professional collaborative studies of interacting binaries
from National Undergraduate Research Observatory (NURO) observations.
The observations were taken by Ron Samec, Danny Falkner, and James
Kring. Reduction and analyzes were mostly done by James Kring and Dr.
Samec. The Lowell 0.81m reflector in Flagstaff, AZ on 2012 September
24, 26, 27, and 29 was used with a CRYOTIGER cooled (-100°C)
2048*2048 NASACAM and standard Johnson-Cousins UBVRcIc filters.
Our 2012 UBVR light curves include 365 U-filter, 375 B, 357 V, 364
Rc, and 367 Ic individual CCD images.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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22 25 16.03 +41 27 51.9 GSC 3208 1986 = TYC 3208-1986-1 (P=0.404562)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 15 1828 UBVRI photometry of GSC 3208-1986
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See also:
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
I/250 : The Tycho Reference Catalogue (Hog+ 1998)
J/AJ/149/48 : BVRI light curves of ZZ Eri (Samec+, 2015)
J/AJ/147/3 : BV(RI)c light curves of V2421 Cyg (Samec+, 2014)
J/AJ/145/14 : BV(RI)c light curves of V1043 Cas (Samec+, 2013)
J/PASP/124/693 : HO Psc UBV(RI)c light curves (Samec+, 2012)
J/AJ/143/99 : Photometry of W UMa eclipsing binaries (Terrell+, 2012)
J/AJ/142/117 : UBVrcIc differential photometry of V1853 Ori (Samec+, 2011)
J/AJ/138/466 : NSVS variables automated classification (Hoffman+, 2009)
J/AJ/131/621 : A catalog of 1022 bright contact binary stars (Gettel+, 2006)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- Flt [UBVRI] Filter (Johnson-Cousins UBVRI)
3- 8 F6.3 mag Dmag Δ magnitude in filter (in the sense of
variable minus comparison star GSC 3208-1967) (1)
10- 15 F6.4 d HJD Heliocentric Julian Date (HJD-2456190)
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Note (1): The standard error of a single observation was 6mmag in U, B and V,
4mmag in Rc and Ic.
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 16-Mar-2015