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\begin{document}
\IBVShead{4168}{9 March 1995}

\title{PERIOD CORRECTION FOR THE NEW ECLIPSING BINARY DHK\,41}

\begintext

Recently, Kaiser (1994) announced that the 9th magnitude G0 star 
HD\,284195
= SAO\,76494 is a detached eclipsing binary, which he designated
DHK\,41 in his discovery list. He reported a preliminary period of 3.176 days. 
However, JG and BH soon observed the non-occurrence of an eclipse predicted
by this period.

Continued visual monitoring by MEB and CS revealed that this eclipsing
binary has an eccentric orbit with secondary minimum occurring at phase 0.3.
The reported period, 3.176 days, is actually the interval from secondary 
minimum to the following primary minimum in a true period of 4.5 days.

Table 1 contains heliocentric times of minima obtained to date. DHK, DT, JG,
and BH have observed photoelectrically, MEB and CS have monitored the star 
visually. The photoelectric timings were reduced with a program based on
the Kwee--Van Woerden (1956) method, and the mean errors are given. These
errors are large for photoelectric data, due mostly to poor observing
conditions.

The period was determined by least  squares using the minima from Table 1.
The data were weighted as follows, discovery photograph 1, visual 3 and
photoelectric 10. The O$-$C residuals in the table were calculated according to the following light elements:
\vskip 1mm
\hspace*{3cm}Min.\,I=HJD\,2\,449\,701.7062+4\fd 49407$\times$E \hfill (1)
\hspace*{6.9cm}$\pm$0.0004 $\pm$\,.00005
\vskip 1mm
\epsfysize=8.5cm
\centerline{\epsffile{4168-f1.ps}}
\centerline{Figure 1}
\vfill \eject

\centerline{2}
\vskip 1mm
\centerline{Table 1}
\vskip 1mm
\begin{center}
\begin{tabular}{rclrl}
\hline
HJD 2400000+&Min.& &O$-$C&Observer\\
\hline
\\
49602.846&I&ptg$^{\star}$&+0.008&Kaiser\\
49653.632&II&vis&$-$0.004&Baldwin\\
49680.597&II&vis&$-$0.003&Baldwin\\
49701.7061&I&pep&0.000&Terrell\\
$\pm$0.0013& & & & \\
49707.5649&II&pep&0.001&Kaiser\\
$\pm$0.0018& & & & \\
49755.6355&I&pep&0.001&Kaiser\\
$\pm$0.0020& & & & \\
\hline
\end{tabular}
\end{center}
\vskip 2mm
$^{\star}$ -- Discovery photograph
\vskip 4mm

Figure 1 has DHK's V data and DT's delta V data merged into one graph to
show phase coverage. The two eclipses are nearly equal in depth, about 0.44 V.
At this time, our choice of primary eclipse is nominal, the slightly greater
apparent depth of Min.\,I being similar to the scatter in the observations.

In a poster paper  presented at the January 1995 meeting of the American
Astronomical Society (Terrell and Kaiser, 1994), DT and DHK estimated the
orbital eccentricity to be near 0.3 and noted that the star may be a distant
member of the Hyades cluster. Photoelectric and radial velocity observations of
this interesting binary system are continuing, and a full analysis will be
published when these observations have been completed.
\vskip 1cm

\beginauthors
Daniel H. KAISER
2631 Washington Street
Columbus, IN 47201, U.S.A.
\vskip 2mm
Marvin E. BALDWIN
8655 N. Co. Rd. 775 E.
Butlerville, IN 47223, U.S.A.
\vskip 2mm
Jerry GUNN
606 Skyview Drive
East Peoria, IL 61611, U.S.A.
\vskip 1.3cm
\authorsrightcol
Dirk TERRELL
Department of Physics \&
Astronomy
University of Calgary
Calgary, Alberta T2N 1N4
Canada
\vskip 2mm
Chris STEPHAN
219 Andretti Avenue
Sebring, FL 33870, U.S.A.
\vskip 2mm
Brian HAKES
7059 N. Fox Point Drive
Peoria, IL 61615, U.S.A.
\endauthors

\references

Kaiser, D. H., 1994, {\it IBVS}, No.\,4119

Kwee, K. K., and Van Woerden, H., 1956, {\it BAN}, {\bf 12}, No.\,464, 327

Terrell, D., and Kaiser, D. H., 1994, {\it BAAS}, {\bf 26}, No.\,4, 1461
(abstract)

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