\documentstyle[twoside, ibvs2, epsf]{article}

\input ibvst.sty
\input ibvse.sty
\input epsf.sty

\begin{document}

\IBVShead{5541}{5 July 2004}

\IBVStitletl{CCD Light Curves of ROTSE1 Variables, XXII: GSC\,2533:1519 CV\lowercase{n,}}{ GSC\,2534:1121 CV\lowercase{n,} GSC\,2537:520 CV\lowercase{n} and GSC\,2544:1007 CV\lowercase{n}}

\IBVSauth{Bl\"attler, E.$^1$; Diethelm, R.$^2$}
   
\IBVSinst{BBSAG, Sch\"usselacher 1, CH-8636 Wald, Switzerland; e-mail: 
blaettler-
wald@bluewin.ch}

\IBVSinst{BBSAG, Bahnhofstrasse 3, CH-4118 Rodersdorf, Switzerland; e-mail: 
diethelm@astro.unibas.ch}

\SIMBADobj{ROTSE1 J124033.39+342255.8}
\SIMBADobj{ROTSE1 J130625.38+342917.7}
\SIMBADobj{ROTSE1 J134117.73+315429.5}
\SIMBADobj{ROTSE1 J135313.76+322248.9}

\begintext

\IBVSEobs{Private observatory Sch\"usselacher, Wald, 0.15-m Starfire refractor}

\IBVSEdet{SBIG ST-7 CCD camera}

\IBVSEred{Standard CCD-frame reduction using AIP4WIN software}

\IBVSEmethod{Kwee -- van Woerden algorithm}

{\small
\IBVSEstarlis{GSC\,2533:1519 &&&& \\
ROTSE1 J124033.39+342255.8 & EW & 12 40 33.4 & +34 22 56 & GSC\,2533:1553 / 
GSC\,2533:1207 \\
 GSC\,2534:1121 &&&& \\
ROTSE1 J130625.38+342917.7 & EW & 13 06 25.4 & +34 29 18 & GSC\,2534:1056 / 
GSC\,2534:1091 \\
 GSC\,2537:520 &&&& \\
ROTSE1 J134117.73+315429.5 & EB & 13 41 17.7 & +31 54 30 & SAO\,63685 / 
GSC\,2537:909 \\
 GSC\,2544:1007 &&&& \\
ROTSE1 J135313.76+322248.9 & EW & 13 53 13.8 & +32 22 49 & GSC\,2544:976 / 
GSC\,2544:1098 \\}


\IBVSEephem{ROTSE1 J124033.39+342255.8 & 53094.6168(13) & 0.491421 & present 
paper \\
ROTSE1 J130625.38+342917.7 & 53060.5691(9) & 0.342687 & " \\
ROTSE1 J134117.73+315429.5 & 53094.3741(8) & 0.371039 & " \\
ROTSE1 J135313.76+322248.9 & 53117.3815(8) & 0.315367 & " \\}

}

\IBVSEmin{
GSC2533:1519 (CVn) & 51275.8649 & 7 & p & none && ROTSE1 \\
		& 51296.757 & 2 & s & none && ROTSE1 \\
                        & 53045.4713 & 11 & p & none && \\
                        & 53060.4671 & 20 & s & none && \\
                        & 53060.706 & 3 & p & none && \\
                        & 53068.5686 & 8 & p & none && \\
                        & 53081.347 & 3 & p & none && \\
                        & 53094.3764 & 19 & s & none && \\
                        & 53094.6153 & 12 & p & none && \\
		& 53117.4705 & 14 & s & none && \\
GSC2534:1121 (CVn) & 51244..6674 & 9 & p & none && ROTSE1 \\
		& 51338.7449 & 7 & s & none && ROTSE1 \\
                        & 53045.4896 & 15 & p & none && \\
		& 53060.3985 & 18 & s & none && \\
                        & 53060.5698 & 12 & p & none && \\
                        & 53068.4488 & 17 & p & none && \\
                        & 53081.4698 & 20 & p & none && \\
                        & 53094.3252 & 23 & s & none && \\
                        & 53094.4965 & 10 & p & none && \\
		& 53117.4565 & 8 & p & none && \\
                        & 53117.6272 & 25 & s & none && \\
GSC2537:520 (CVn) & 51248.8222 & 8 & p & none && ROTSE1 \\
		& 51348.8239 & 15 & s & none && ROTSE1 \\
                        & 53045.5866 & 18 & s & none && \\
		& 53060.4205 & 10 & s & none && \\
                        & 53060.6083 & 12 & p & none && \\
                        & 53068.402 & 6 & p & none && \\
                        & 53068.5850 & 6 & s & none && \\
                        & 53081.3868 & 19 & p & none && \\
                        & 53094.3736 & 13 & p & none && \\
		& 53094.5600 & 17 & s & none && \\
                        & 53117.3783 & 14 & p & none && \\
                        & 53117.5665 & 16 & s & none && \\
GSC2544:1007 (CVn) & 51251.8239 & 7 & s & none && ROTSE1 \\
		& 51259.872 & 5 & p & none && ROTSE1 \\
		& 53045.4760 & 9 & p & none && \\
                        & 53060.4579 & 13 & s & none && \\
                        & 53060.6181 & 20 & p & none && \\
                        & 53068.4984 & 18 & p & none && \\
                        & 53081.4294 & 19 & p & none && \\
                        & 53094.3569 & 12 & p & none && \\
                        & 53094.5212 & 21 & s & none && \\
                        & 53117.3811 & 17 & p & none && \\
		& 53117.5393 & 11 & s & none && \\
}
                       	
\IBVSEremexp{ROTSE1: Observations of Akerlof et al. (2000).}

\IBVS2fig{7cm}{5541-f1.eps}{CCD light curve (without filter) of GSC\,2533:1519}{5541-f2.eps}{CCD light curve (without filter) of GSC\,2534:1121}

\IBVSfigKey{5541-f1.eps}{GSC 2533-1519}{light curve}
\IBVSfigKey{5541-f2.eps}{GSC 2534-1121}{light curve}


\IBVS2fig{7cm}{5541-f3.eps}{CCD light curve (without filter) of GSC\,2537:520}{5541-f4.eps}{CCD light curve (without filter) of GSC\,2544:1007}

\IBVSfigKey{5541-f3.eps}{GSC 2537-520}{light curve}
\IBVSfigKey{5541-f4.eps}{GSC 2544-1007}{light curve}

\vspace*{-0.5cm}

\IBVSErem{
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) in the list of Akerlof et al. (2000). This installment 
contains information on four variables in the constellation Canes Venatici. 
The four stars were observed with our CCD equipment during seven nights 
between JD\,2453045 and JD\,2453117. A total of 194 CCD frames were measured of 
GSC\,2533:1519, 206 frames of GSC\,2534:1121, 185 frames of GSC\,2537:520 as 
well as 178 frames of GSC\,2544:1007. Figures 1 through 4 show our observations 
folded with the elements given in the Table of Ephemeris.  
These elements of variation are deduced from a linear fit to the normal 
minima from the ROTSE1 data and the timings of minimum derived from our data 
given in the table of Times of minima.}


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


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

\vspace*{-0.5cm}

\reference

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

\end{document}


