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\begin{document}

\IBVShead{5084}{23 May 2001}

\IBVStitle{Two New Algol-type Eclipsing Binaries}

\IBVSauth{Williams, David B.}

\IBVSinsto{P. O. Box 58, Whitestown, IN 46075 USA, e-mail: dbwilyumz@aol.com}

\SIMBADobj{GSC 5409-1201}
\SIMBADobj{GSC 3002-0454}

\IBVSabs{Two new Algol-type eclipsing binaries are reported,}
\IBVSabs{GSC 5409-1201, P = 10.984156 d, 12.8-<15.0 m(ptg) and}
\IBVSabs{GSC 3002-0454, P = 1.8559010 d, 13.6-<15.0 m(ptg).}

\begintext

This report presents some results of a search for new variable
stars conducted with the 25-cm photographic refractor ($f/6.3$
Cooke triplet) and blink comparator at Indiana University's
Goethe Link Observatory, made available through a cooperative
arrangement with the Indiana Astronomical Society. The
blue-corrected astrograph recorded a field of $6.4 \times 8.0$ degrees
on $20\times25$-cm Kodak SB-5 X-ray film (blue sensitive) and reached a
limiting magnitude of 15.0 $B$ in a 30-minute exposure.

The two eclipsing variables listed below are not officially
designated in the General Catalogue of Variable Stars or
subsequent Name Lists. Following the detection of variability at
Link, each star was investigated at the Harvard College
Observatory plate collection to confirm variability and determine
the type and period. Magnitudes of comparison star sequences were
determined by eye estimates using photoelectric $B$ magnitudes of
stars in nearby fields of the Guide Star Photometric Catalogue
(Lasker et al.\ 1988).

{\bf GSC 5409-1201 (Pup).} (07\hr30\mm01\fsec7
$-$14\deg28\arcm22\farcs8 (B1950); type EA, 12.8--$<$15.0 $m_{\rm
ptg}$.) Discovery of variability was first mentioned briefly in
Williams (1996). Observed on 543 Harvard plates. Depth of minimum
remains uncertain, variable fainter than plate limit. Duration of
primary minimum is about 0.09 $P$. Magnitude estimates were recorded
for each of the first 119 plates. To save time, only observations
fainter than maximum were recorded from the remaining 424 plates.
These observations are listed electronically as 5084-t3.txt, available
through the IBVS Web site. The following light elements were
determined by least squares analysis of the 19 observations of the
variable at least 1 magnitude below maximum, 13.8 $m_{\rm ptg}$ or
fainter (Table 1):

$$ \begin{array}{r@{}r@{}l}
{\rm Min.~I = HJD~} 2432891.408 & {} + 10\fday984156 & {} \times E.\\
\pm 0.061 & {} \pm 0.000075 \\
\end{array} $$

The $O-C$ residuals in Table 1 and the light curve (Figure 1) are
based on these elements. The period is just 20 minutes longer
than 11 sidereal days.

\newpage

\begin{center}
{\normalsize Table 1: Plate minima, GSC 5409-1201}
\vskip2mm
\begin{tabular}{crrr}
\hline
HJD 2400000\,+ & Mag (ptg)& Epoch & $O-C$ (days)\\
\hline
25619.516& 14.1 & $-$662 & $-$0.381\\
25982.473 & $<$15.0 & $-$629 & +0.099\\
26762.318 & $<$14.0 & $-$558 & +0.069\\
28596.530 & $<$15.0 & $-$391 & $-$0.073\\
28596.577 & $<$14.0 & $-$391 & $-$0.026\\
28837.861 & 14.1 & $-$369 & $-$0.394\\
28848.849 & 14.2 & $-$368 & $-$0.390\\
28937.401 & $<$14.0 & $-$360 & +0.289\\
29585.435 & 14.7 & $-$301 & +0.258\\
29717.359 & 13.9 & $-$289 & +0.372\\
32891.575 & $<$15.0 & 0 & +0.167\\
32891.587 & $<$15.0 & 0 & +0.179\\
42447.658 & $<$14.0 & 870 & +0.035\\
45753.942 & 14.2 & 1171 & +0.088\\
46115.961 & $<$14.0 & 1204 & $-$0.370\\
46116.032 & $<$14.5 & 1204 & $-$0.299\\
46446.025 & 13.9 & 1234 & +0.169\\
47258.823 & 14.4 & 1308 & +0.139 \\
49389.671 & $<$15.0 & 1502 & +0.061\\
\hline
\end{tabular}
\end{center}

\IBVSfig{11cm}{5084-f1.eps}{Photographic phased light curve, GSC
5409-1201}

\newpage

\begin{center}
{\normalsize Table 2: Plate minima, GSC 3002-0454}
\vskip2mm
\begin{tabular}{crrr}
\hline
HJD 2400000\,+ & Mag (ptg)& Epoch & $O-C$ (days)\\
\hline
25290.813 & $<$14.2 & $-$4732 & +0.119\\
27092.797 & 14.2 & $-$3761 & +0.015\\
27374.884 & $<$14.8 & $-$3609 & +0.003\\
27532.588 & 14.7 & $-$3524 & $-$0.045\\
28961.655 & 14.6 & $-$2754 & $-$0.029\\
29429.655 & 14.4 & $-$1963 & $-$0.054\\
31084.864 & $<$14.5 & $-$1610 & +0.019\\
34072.774 & 14.5 & 0 & $-$0.086\\
42485.727 & 14.4 & 4533 & +0.027\\
44996.764 & $<$14.5 & 5886 & +0.018\\
45289.892 & 14.2 & 6044 & $-$0.088 \\
45757.717 & 14.2 & 6296 & +0.048\\
46438.810 & $<$14.2 & 6663 & +0.022\\
46492.646 & $<$14.5 & 6692 & +0.036\\
46878.712 & 14.1 & 6900 & +0.073\\
47264.629 & $<$14.5 & 7108 & $-$0.039\\
49801.651 & $<$15.0 & 8475 & $-$0.046\\
\hline
\end{tabular}
\end{center}

\IBVSfig{11cm}{5084-f2.eps}{Photographic phased light curve, GSC
3002-0454}

\newpage

{\bf GSC 3002-0454 (UMa).} (10\hr26\mm56\fsec4,
$+$40\deg11\arcm51\farcs0 (B1950); type EA, 13.6--$<$15.0 $m_{\rm
ptg}$.) Observed on 142 Harvard plates (magnitude estimates available
electronically as 5084-t4.txt through the IBVS Web site). Faint or
invisible on 17 plates, but these observations do not define the times
of mid-eclipse very well because the minima are much deeper than the
faint limit on the patrol plates. As a result, attempts to find the
period were frustrated by sidereal day aliases. Visual monitoring by
M. E. Baldwin and P. R. Guilbault revealed that the period is close to
1\fday856. The following light elements were determined by least
squares analysis of the 17 times when GSC 3002-0454 was fainter than
maximum (Table 2):
$$ \begin{array}{r@{}r@{}l}
{\rm Min.~I = HJD~} 2434072.860 & {} + 1\fday8559010 & {} \times E.\\
\pm 0.015 & {} \pm 0.0000003 \\
\end{array} $$

The $O-C$ residuals in Table 2 and the light curve (Figure 2) are
based on these elements. New visual and CCD times of minima,
$BVRI$ photometry, and light curve parameters will appear in
Baldwin et al.\ (2001).

I wish to thank the Indiana University Astronomy Department for
use of the Link Observatory facilities. I am also grateful to
Martha Hazen for extensive use of the Harvard plates, to M. E.
Baldwin and P. R. Guilbault for finding the period of GSC
3002-0454, and to Guilbault and G. W. Billings for preparing this
report for publication.

\IBVSedata{5084-t3.txt}
\IBVSedata{5084-t4.txt}

\references

Baldwin, M. E., Guilbault, P. R., Henden, A. A., Kaiser, D. H.,
Lubcke, G. C., Samolyk, G., and Williams, D. B., 2001, {\it Journ.\
Amer.\ Assoc.\ Var.\ Star Obs.}, Vol.\ 29, No.\ 2, in press

Lasker, B., Sturch, C., Conrad, R., et al., 1988, {\it Astrophys.\ Journ.\
Suppl.}, {\bf 68}, 1 (Guide Star Photometric Catalogue)

Williams, D. B., 1996, {\it Journ.\ Amer.\ Assoc.\ Var.\ Star Obs.}, {\bf 25}, 30

\endreferences

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