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\IBVShead{4384}{23 October 1996}

\title{1996 PHOTOMETRY OF RT ANDROMEDAE}
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\begintext

	RT Andromedae (=BD +52\degr\ 3383A=\#201 in the catalog of Strassmeier et al. 
1993) is a member of the short period eclipsing group of RS CVn stars.  Zeilik et al. 
(1989) modeled the spot structure for available data from 1920 to 1989 and reviewed 
previous work.  Heckert (1995) model the spots on RT And during 1995.  Building on the 
above work we model the spot structure during 1996.
	We observed RT And on the nights of 2, 3, 4, and 8 January 1996 using the San 
Diego State University 61-cm telescope on Mt. Laguna.  We used the same instrument, 
technique, and calibration as described by Heckert (1995).  The light curves contain a few 
gaps, most noticeably just before the eclipses and during the first half of the primary 
eclipse.  The data are however sufficient to model the spots.  Figures 1 and 2 show 
differential magnitudes (star$-$comparison) in the standard Johnson--Cousins system.  The 
data are available in digital form from PAH.
	Budding and Zeilik (1987) describe in detail the Information Limit Optimization 
Technique (ILOT) that we used to model the data.  We performed the initial fits, starting 
with the orbital parameters found by Zeilik et al. (1989).  Unlike most of the short period 
RS CVns, RT And has an elliptical orbit.  However, we were unable to fit the ellipticity 
parameters and kept them fixed at the initial values.  From the initial fits, we extracted a distortion wave and fit it to the longitude and radius of a single circular spot at 0K.  With 
the exception of the B band, we were unable to fit for the latitude simultaneously with the 
other parameters and used a fixed latitude of 45\degr.  The fits for each wavelength are 
performed independently.  We get:
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\centerline{Spot Fits}
\begin{center}
\begin{tabular}{lllll}
\hline
	&B band	&V band	&R band	&I band\\
\hline
\\
Longitude&	217.5$\pm$3.6&	223.1$\pm$4.3&	213.6$\pm$5.2&
	209.8$\pm$5.8\\
Latitude&	38.9$\pm$16.6&	45&	45&	45\\
Radius&	11.7$\pm$2.3&	12.2$\pm$0.6&	11.7$\pm$0.7&
	11.7$\pm$0.8\\
$\chi^2$&	112.1&	58.0&	73.6&	119.5\\
\hline
\end{tabular}
\end{center}
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	Figures 3 and 4 show the initial and spot fits in the V band.  We did not attempt to do clean fits to remove the spot effects and find the binary star parameters because the 
incompleteness of the primary eclipse would reduce the confidence in such solutions.  
These results are similar to the previous long term trend found by Zeilik et al. (1989).  A 
single spot in one of two Active Longitude Belts fits the data well.  Comparing these 
results to those of Heckert (1995), we find that the spot in 1996 was roughly the same 
size as in 1995 but was in the opposite active longitude belt.  We also note that in 1996 
the spot was near the edge of the 270\degr\ active longitude belt.  In both this and 
previous work the spots seem to be at middle latitudes, but the latitude fits generally have low confidence and were usually fixed at 45\degr\ rather than fit to the data.
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\centerline{2}
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\centerline{Figure 1.  RT And 1996 B and V light curves}
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\centerline{Figure 2.  RT And 1996 R and I light curves}
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\centerline{3}
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\centerline{Figure 3.  RT And 1996 V band initial fit}
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\centerline{Figure 4.  RT And 1996 V band spot fit}
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\centerline{4}
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	We thank Ron Angione for scheduling very generous amounts of observing time at 
Mt. Laguna. PAH acknowledges support from the Cottrel College Science Program of the 
Research Corporation.  MRB and KP acknowledge support from the Summer Ventures in 
Science and Mathematics Program at Western Carolina University.


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\beginauthors
\authorsrightcol
PAUL A. HECKERT
Dept. of Chem. \& Physics
Western Carolina University
Cullowhee, NC 28723   USA
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MELINDA R. BEAVER
Summer Ventures Program
Western Carolina University
and Alexander Central High School
Taylorsville, NC 28681   USA
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KELLY PHILLIPS
Summer Ventures Program
Western Carolina University
and Wilkes Central High School
Wilkesboro, NC 28697   USA
\endauthors

\references

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

Heckert, P.A., 1995, {\it Inf. Bull. Var. Stars}, No.\,4224

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

Zeilik, M., Cox, D.A., De Blasi, C., Rhodes, M., and Budding, E., 1989, {\it Astrophys. 
J.}, {\bf 345}, 991

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