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\IBVShead{4303}{6 March 1996}

\title{1995 PHOTOMETRY OF SV CAMELOPARDALIS}
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\begintext

	SV Camelopardalis (= SAO 1038 =\#65 in the catalog of Strassmeier et al.
 1993) is a member of the short period group of eclipsing RS CVn systems.  Budding
 and Zeilik (1987) first modeled the starspots on this system and Zeilik et al.
 (1988) modeled the starspots for data available over the previous half century.
  Sarma et al. (1991) have also modeled the spots on this system.  Continuing 
this work, I obtained BVRI light curves during 1995 and modeled the starspot 
structure.
	I observed SV Cam on the nights of 22, 28, 30, and 31 January and 1 and 4 February 1995 with the San Diego State University 61-cm telescope on Mt. 
Laguna.  The photometer has a Hamamatsu R943-02 tube cooled to $-$15\degr C\ and 
operated at $-$1450V.  Following Patk\'os (1982), I used SAO\,1020 (=BD +82\degr 168 = HD\,43883) 
as the comparison star.  In over seven years of photometry of SV Cam, Patk\'os found 
no evidence of variability of this comparison star.  Using Landolt standard stars, 
I transformed the data into differential magnitudes in the standard Johnson 
Cousins system.  Figures 1 and 2 show the differential (star--comparison) 
magnitudes in the BVRI bands.
	I modeled the data with the Information Limit Optimization Technique 
(ILOT) of Budding and Zeilik (1987).  I started with the various stellar and 
orbital parameters from Budding and Zeilik (1987) and Zeilik et al. (1988) to 
perform initial fits to the data.  The ILOT programs then subtract eclipse 
effects from the data and fit starspots to the remaining distortion wave.  
These SV Cam data fit best with two spots.  Figure 3 shows the V band spot fit.  
The results in degrees are:


\vskip 2mm
\centerline{Spot fits}
\begin{center}
\begin{tabular}{lllll}
\hline

	&B band	&V band	&R band&	I band\\
\hline
\\
Longitude$_1$&	289.8$\pm$1.8&	300.0$\pm$3.3&	299.2$\pm$3.9&	302.3$\pm$5.2\\
Latitude$_1$&	$-$0.1$\pm$12.1&	$-$0.5$\pm$18.8&$-$1.5$\pm$27.4&	0(fixed)\\
Radius$_1$&	11.6$\pm$0.4&	9.0$\pm$0.4&9.1$\pm$0.5	&8.3$\pm$0.5\\
Longitude$_2$&	81.6$\pm$2.5&	62.5$\pm$4.0&	60.0$\pm$5.4&	61.9$\pm$8.3\\
Latitude$_2$&	0.0$\pm$14.5&	0.2$\pm$20.0&$-$1.4$\pm$44.4&$-$0.2$\pm$29.2\\
Radius$_2$&10.6$\pm$0.4&	8.0$\pm$0.5&	7.3$\pm$0.6	&5.8$\pm$0.8\\
$\chi^2$&168.2&	176.0&	123.2&	118.8\\
\hline
\end{tabular}
\end{center}
\vskip 5mm
	The spot models of Zeilik et al. (1988) show that over a 50 year span 
one fairly large high latitude spot tends to fit the data.  These 1995 data are fit best with two low latitude spots, an apparently unusual occurrence for this system.  Both spots are however located in the active longitude belts (ALBs) at roughly 90\degr\ and 270\degr\ noticed by Zeilik et al. (1988).  After finding 
the best spot fits, the ILOT programs allow one to subtract the spot effects to perform clean fits to the data.  Figure 4 shows the initial and clean fits for 
the V band.  For the clean fits, I get:
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\centerline{2}
\vskip 1mm
\centerline{Clean fits}
\begin{center}
\begin{tabular}{lllll}
\hline

	&B band	&V band&	R band	&I band\\
\hline
U&	1.022$\pm$0.001&	0.991$\pm$0.001&	0.973$\pm$0.002&	0.979$\pm$0.001\\
L$_1$&	1.018$\pm$0.005&	0.968$\pm$0.005&	0.898$\pm$0.016&	0.905$\pm$0.005\\
k(=r$_2$/r$_1$)&	0.635$\pm$0.004&	0.625$\pm$0.006&	0.846$\pm$0.047&	0.618$\pm$0.006\\
r$_1$&	0.355$\pm$0.004&	0.348$\pm$0.004&	0.316$\pm$0.009&	0.347+0.004\\
i(deg)&	87.6$\pm$1.7&	87.1$\pm$1.3&	77.7$\pm$0.7&	86.8$\pm$1.4\\
L$_2$&	0.004$\pm$0.006&	0.023$\pm$0.006&	0.075$\pm$0.018&	0.074$\pm$0.007\\
q(=M$_2$/M$_1$)&	0.439$\pm$0.028&	0.449$\pm$0.034&	0.865$\pm$0.114&	0.517$\pm$0.050\\
$\chi^2$&	69.4	&65.9&	84.8&	80.5\\
\hline
\end{tabular}
\end{center}

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\centerline{Figure 1. B and V light curves of SV Cam in Jan/Feb 1995.}
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\centerline{\epsffile{4303-f2.ps}}
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\centerline{Figure 2. R and I light curves of SV Cam in Jan/Feb 1995.}

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\centerline{3}
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\centerline{Figure 3. V band spot fit for Jan/Feb 1995.}
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\centerline{\epsffile{4303-f4.ps}}
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\centerline{Figure 4. SV Cam - Jan/Feb 1995. Initial and clean fits for the V 
band.}
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	The clean fit parameters are as defined by Budding and Zeilik (1987).  
L$_1$ and L$_2$, the fractional luminosities of the primary and secondary stars, 
sum to the unit of light, U, in the absence of a third light.  Rainger et al. 
(1991) and Sarma et al. (1989, 1991) find evidence for a third component in this 
system, but I was unable to find evidence for a third light from my data.  Note that the secondary is much fainter than the primary; if the third component were 
fainter than the secondary, it would not be detectable with this photometry.  
The primary and secondary radii, r$_1$ and r$_2$, are in units of the semi-major 
axis of the orbit, and i is the orbital inclination.  The mass ratio from these models is somewhat lower than the usual value of 0.6 to 0.7 (Budding and Zeilik 1987, 
Sarma et al. 1989, Patkos and Hempelmann 1994)  Otherwise these clean fits agree fairly well with the values 
found by Zeilik et al. (1988).
	

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\centerline{4}
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I thank Ron Angione for scheduling very generous amounts of observing 
time at Mt. Laguna.  I received support from the American Astronomical Society 
Small Grants Program for this work.  I also acknowledge both financial support 
and a Faculty Scholarly Development Assignment Program Leave from Western 
Carolina University.

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\beginauthors
\authorsrightcol
P.A. HECKERT				
Dept. of Chem. \& Physics		
Western Carolina University		
Cullowhee, NC 28723 
USA		
\endauthors


\references

Budding, E. and Zeilik, M., 1987, {\it Astrophys. J.}, {\bf 319}, 827

Patk\'os, L., 1982, {\it Comm. Konkoly, Obs.}, No.\,80.
\IBVSlink{http://www.konkoly.hu/Mitteilungen/80.html}

Patk\'os, L. and Hempelmann, A., 1994, {\it Astron. \& Astrophys.}, {\bf 292}, 119

Rainger, P.P., Hilditch, R.W., and Edwin, R.P., 1991, {\it MNRAS}, {\bf248}, 168

Sarma, C.V.S.R., Sarma, M.B.K., and Sanwal, N.B., 1989, {\it J. Astrophys. Astron.}, {\bf 10}, 307

Sarma, C.V.S.R., Vivekananda Rao, P., and Sarma, M.B.K., 1991, {\it J. Astrophys. Astron.}, {\bf 12}, 49

Strassmeier, K., et al., 1993, {\it Astron. \& Astrophys. Suppl.}, {\bf 100}, 173

Zeilik, M., De Blasi, C., Rhodes, M., and Budding, E., 1988, {\it Astrophys. J.}, {\bf 332}, 293

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