\documentstyle[twoside,epsf]{article}

\input ibvs2.sty
\input ibvst.sty

\begin{document}

\IBVShead{5001}{12 December 2000}

\IBVStitle{GSC 5728\_92: a New W UM\lowercase{a} Variable}

\IBVSauth{Rea, Robert D.$^1$; Walker, W. S. G.$^2$}

\IBVSinst{Regent Lane Observatory, Nelson, New Zealand, email: reamarsh@ihug.co.nz}

\IBVSinst{Wharemaru Observatory, Kaitaia, New Zealand, email: astroman@voyager.co.nz}

\SIMBADobj{GSC 5728-92}

\begintext

\IBVSTnam{GSC 5728\_92}

\IBVSTcoo{19\hr40\mm08\sec}{$-10$\deg22\arcm26\farcs}{J2000}

\IBVSTobs{Regent Lane Observatory, 0.35-m Schmidt--Cassegrain telescope;\\
Wharemaru Observatory, 0.25-m Schmidt--Cassegrain telescope}

\IBVSfig{9cm}{5001-f1.ps}{Phase diagram of GSC 05728\_00092}

\IBVSTdet{Santa Barbara Instruments Group ST6B}

\IBVSTfil{None, roughly $R$}

\IBVSTcomp{GSC 5728\_410; GSC 5728\_248 (for observations on Oct.\ 9
and Oct.\ 16, 2000, with 0.35-m Schmidt--Cassegrain)}

\IBVSTsysn

\IBVSTdata{Upon request}

\IBVSTrem{
The variability of GSC 5728\_92 was initially noticed while reducing
data obtained on October 9th, 2000 while monitoring V1432 Aquilae as
part of the Center for Backyard Astrophysics program of investigating
CV stars.  GSC 5728-92 was being investigated as a possible check star
for CCD photometry, but the measured standard deviations indicated it
was unsuitable, and further investigation showed it declined in
brightness by about 0.3 magnitudes over a time period of approximately
two hours.  Data acquired previously  (September 27) at Wharemaru
Observatory confirmed the variability.\\
Further data was gathered on when weather permitted until October 31.\\
Analysis of the data yields an ephemeris:
$${\rm Minimum = HJD}~2451814.642 + 0\fday4636 \times E.$$
The fit is reasonable and the star is certainly a W Ursae Majoris binary.\\
The amplitude measured at Regent Lane Observatory is similar but offset
from than that obtained at Wharemaru Observatory.  The data are in
the natural telescope/CCD systems, hence the offset.  No
extinction corrections have been applied hence the slopes on the
different nights do not match.}

\end{document}
