J/A+A/403/637 V and R light curves of GSC 3822-1056 (Csizmadia+, 2003)
Photometric Study of the Over-Contact Binary Star GSC 3822-1056.
Csizmadia Sz., Biro I>B>, Borkovits T.
<Astron. Astrophys. 403, 637 (2003)>
=2003A&A...403..637C 2003A&A...403..637C
ADC_Keywords: Binaries, eclipsing ; Photometry, UBV ; Photometry, Cousins
Keywords: techniques: photometric - stars: binaries: eclipsing -
stars: binaries: close - stars: individual: GSC 3822-1056
Abstract:
Here we present the first Johnson-Cousins VRC light curves of the
over-contact binary star GSC 3822-1056. A period study and the light
curve solution are also given. An extremely high rate of period
increase +11.6sec/century was found. The origin of this period change
can be: (i) partly covered light-time effect due to the orbital motion
around the mass center of a possible third body; (ii) mass transfer
between the components. The light curve was solved by the 1998
Wilson-Devinney Code. We examined the light curve with and without
third light. Both solutions yielded a contact configuration with high
temperature difference between the components. Despite the high degree
of the contact (f=0.57), the temperature difference between the
components ΔT=Tprimary-Tsecondary=1045K. The high mass-ratio
of the system and its other unusual properties suggest that GSC
3822-1056 may be a recently formed contact binary.
Description:
The object we studied were observed with a Wright Instruments
1024x1024 CCD camera mounted on the 80 cm "IAC80" telescope at
Observatorio del Teide in Tenerife, Spain, operated by Instituto de
Astrofisica de Canarias using Johnson-Cousins V and RC filters.
Typical integration times were 20s for V and 10s for RC bands
respectively. 2x2-pixel binning was used to obtain an optimal
sampling of the star profiles of FWHM nearly equal to 3 pixels, and
only a subframe of size 3x7 arcminutes, containing DW UMa and the two
comparison candidates GSC 3822-1056 (which is actually a W UMa-type
variable and our study is on this star) and GSC 3822-0070. In this way
the time between frames was shortened to 5 seconds.
Objects:
----------------------------------------------------------
RA (2000) DE Designation(s)
----------------------------------------------------------
10 33 57.8 +58 52 16 GSC 3822-1056
10 33 48.9 +58 52 31 GSC 3822-0070
----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2a.dat 20 271 GSC 3822-1056 Johnson V light curve
table2b.dat 20 244 GSC 3822-1056 Cousins R light curve
table2c.dat 30 1091 GSC 3822-1056 relative magnitude to GSC 3822-0070
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2a.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian date
15- 20 F6.3 mag Vmag Johnson V magnitude of GSC 3822-1056
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2b.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian date
15- 20 F6.3 mag Rmag Cousins R magnitude of GSC 3822-1056
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2c.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 F13.5 d HJD Heliocentric Julian date
17- 22 F6.3 mag Dmag Unfiltered magnitude of GSC 3822-1056
relative to GSC 3822-0070
26- 30 F5.3 mag e_Dmag Scatter of measurement of Dmag
--------------------------------------------------------------------------------
Acknowledgements: Szilard Csizmadia
(End) Patricia Bauer [CDS] 15-Apr-2003