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\input ibvs2.sty
\input ibvst.sty

\begin{document}

\IBVShead{4982}{7 November 2000}

\IBVStitletl{CCD Light Curves of ROTSE1 Variables,}{ V: GSC\,3131.476 Lyrae, GSC\,2646.1938 Lyrae}

\IBVSauth{Bl\"attler, E.$^1$; Diethelm, R.$^2$} 

\IBVSinst{BBSAG, Schl\"usselacher 1, CH-8636 Wald, Switzerland; e-mail: blaettler-wald@bluewin.ch}
\IBVSinst{BBSAG, Rennweg 1, CH-4118 Rodersdorf, Switzerland; e-mail: diethelm@astro.unibas.ch}

\SIMBADobj{GSC 3131-476}
\SIMBADobj{GSC 2646-1938}

\begintext

{\bf VAR1}
\smallskip \hrule

\IBVSTnam{GSC\,3131.476 = ROTSE1 J185052.26+434007.1}

\IBVSTcoo{18\hr 50\mm 52\fsec26}{+43\deg 40\arcm 07\farcs1}{2000.0}

\IBVSTcomp{GSC\,3131.439}

\IBVSTchk{GSC\,3131.522}

\IBVSfig{8cm}{4982-f1.eps}{CCD light curve (without filter) of GSC\,3131.476}

\vfill\eject

{\bf VAR2}
\smallskip \hrule

\IBVSTnam{GSC\,2646.1938 = ROTSE1 J185110.44+353556.1}

\IBVSTcoo{18\hr 51\mm 10\fsec44}{+35\deg 35\arcm 56\farcs1}{2000.0}

\IBVSTcomp{GSC\,2646.1777}

\IBVSTchk{GSC\,2646.1920}

\IBVSfig{8cm}{4982-f2.eps}{CCD light curve (without filter) of GSC\,2646.1938}

\smallskip \hrule

\IBVSTobs{Private observatory, Schl\"usselacher, Wald, 0.15-m refractor}

\IBVSTdet{SBIG ST-7 CCD camera}

\IBVSTfil{None}

\IBVSTdata{Upon request from diethelm@astro.unibas.ch} %email


\IBVSTtyp{ EW } 

\IBVSTrem{
As a byproduct of the ROTSE1 CCD survey, a large number of new
variables have been discovered (Akerlof et al.\ 2000). In a series of
papers, we report unfiltered CCD observations for some of the close
binary systems (type EW and E) in the list of Akerlof et al.\ (2000).
GSC\,3131.476 (VAR1 in this paper) was observed with our CCD equipment
as mentioned above during 4 nights between JD\,2451757 and JD\,2451781,
while the data on GSC\,2646.1938 (here VAR2) was collected during 4
nights between JD\,2451766 and JD\,2451781. A total of 107 CCD frames
were measured for VAR1 and 119 frames for VAR2. Figures~1 and~2 show
these observations folded with the elements
$$\begin{array}{ll}
{\rm GSC\,3131.476\colon} & {\rm JD(min,hel)} = 2451757.4883(5) + 0.2429100(25) \times E,\\
{\rm GSC\,2646.1938\colon} & {\rm JD(min,hel)} = 2451766.6097(3) + 0.2860550(12) \times E.\\
\end{array}$$
These elements of variation are deduced from a linear fit to the newly
determined normal minima from the ROTSE1 data (VAR1:
JDH\,2451257.8242(2), primary, JDH\,2451308.7108(4), secondary; VAR2:
JDH\,2451295.8834(3), secondary, JDH\,2451306.7233(5), primary) as well
as the minima derived from our data and given in Bl\"attler (2000).}

\IBVSTack{This research made use of the Simbad data base, operated
at CDS, Strasbourg, France}

\references

Akerlof, C., Amrose, S., Balsano, R., Bloch, J., Casperson, D., Fletcher,
S., Gisler, G., Hills, J., Kehoe, R., Lee, B., Marshall, S., McKay, T.,
Pawl, A., Schaefer, J., Szymanski, J., Wren, J., 2000, {\it AJ}, {\bf 119}, 1901

Bl\"attler, E., 2000, {\it BBSAG Bulletin}, {\bf 123}, 6

\endreferences

\IBVSerratum{4982}

In IBVS No.~4982 the period of GSC 2646.1938 should read 0\fday2890550 instead of 0\fday2860550.


\end{document}
