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\input ibvs2.sty

\begin{document}

\IBVShead{5490}{9 January 2004}

\IBVStitle{Four New High Amplitude {\large ${\boldmath \delta}$} Scuti Stars}

\IBVSauth{ Wils, Patrick$^1$; Greaves, John$^2$; Otero, Sebasti\'an A.$^3$}
\IBVSinst{Vereniging Voor Sterrenkunde, Belgium; e-mail: patrick.wils@cronos.be}
\IBVSinst{Borrowdale Walk, Northampton, UK}
\IBVSinst{Grupo Wezen 1 88, Centro de Estudios Astron\'omicos (CEA), Liga Iberoamericana de Astronom\'\i a (LIADA); e-mail: varsao@fullzero.com.ar}

\SIMBADobj{GSC 7740-1289}
\SIMBADobj{GSC 6698-302}
\SIMBADobj{GSC 9024-7}
\SIMBADobjAlias{GSC 7892-1411}{NSV 9245}
\GCVSobj{NSV 06068}
\GCVSobj{NSV 09245}

\IBVStyp{  HADS  }
\IBVSkey{Variable stars, SX Phe stars, $\delta$ Scuti stars, HADS}
\IBVSabs{Four new high amplitude delta Scuti variables were found in ASAS3}
\IBVSabs{survey data.}

\begintext

\vspace*{-1cm}

Using ASAS3 survey data (Pojmanski, 2002), a number of selected regions in the Southern sky 
has been examined for new variable stars.  For more details, see Greaves et al. (2004).
This revealed 
four previously unknown high amplitude $\delta$ Scuti variable stars (HADS). 
These are presented in Table~1, which lists the identity, 
coordinates (from UCAC2, Zacharias, et al., 2003), Galactic latitude {\it b}, 
$V$ magnitude range (from ASAS3), 2MASS $J-K_s$ colour, epoch of maximum (HJD~--~2450000) 
and period in days.  An additional column in the
electronic version of the IBVS also provides a link to the source of the data.
Table~2 contains the invariant Fourier parameters to degree 3 (for the definition, see Morgan, 2003),
calculated from the ASAS3 data.
Figs.~1 to 4 provide phase plots for these new HADS variables. \\

Notes on individual stars: 

{\it GSC~7740-1289} and {\it GSC~6698-0302}: The Galactic latitude suggests that these are Population II objects, 
however the proper motions in both cases are very small.  
On the other hand, the periods are a little long for SX Phe stars, although 
neither the 
small proper motions nor the periods are unprecedented for such stars.
Among the HADS, the only confirmed field SX Phe star with a period longer than 0.1 days 
is XX~Cyg (Rodr\'\i guez and Breger, 2001).
A determination of their metallicities or $m_1$ indices via Str\"omgren photometry is necessary 
to show whether these stars are of the SX Phe type instead.
GSC~6698-0302 = NSV~6068, discovered by Hoffmeister (1933).

{\it GSC~9024-0007}: This star is probably reddened, as there are dark and bright nebulae nearby.
Johnson UBV photometry would be useful in this regard.

{\it GSC~7892-1411}: NSV~9245, discovered by Strohmeier (1967).  
Spencer and Jackson (1939) give the spectral type $A3$, $B-V = +0.22$ (ESA, 1997).

{\small
\begin{table}[!hb]
\begin{center}
{\normalsize Table 1. Positional and photometric details for the new HADS.} \vskip2mm
\begin{tabular}{cccrr@{}lrcrrcc} 
\hline
GSC & \multicolumn{2}{c}{RA (J2000) Dec} & {\it b} & \multicolumn{2}{c}{$V$} & $J$--$K_s$ & Epoch & Period & \IBVSshortlink{http://archive.princeton.edu/\char126 asas/}{ASAS3} \\
\hline
7740-1289 & 11 34 44.97 & --38 25 49.1 & +22.0 & 12.26 & -12.67 & +0.14 & 1962.856 & 0.129485 & \IBVSshortlink{http://www.astrouw.edu.pl/cgi-asas/asas_lc/113445-3825.8}{113445-3825.8} \\
6698-0302 & 13 02 45.49 & --23 58 13.2 & +38.8 & 10.84 & -11.46 & +0.20 & 2432.684 & 0.158491 & \IBVSshortlink{http://www.astrouw.edu.pl/cgi-asas/asas_lc/130246-2358.3}{130246-2358.3} \\
9024-0007 & 15 00 12.94 & --62 54 03.2 &  --3.1 & 10.52 & -11.22 & +0.23 & 2832.661 & 0.101565 & \IBVSshortlink{http://www.astrouw.edu.pl/cgi-asas/asas_lc/150013-6254.1}{150013-6254.1} \\
7892-1411 & 17 37 41.71 & --42 31 04.9 &  --5.8 & 10.01 & -10.58 & +0.27 & 2057.700 & 0.117031 & \IBVSshortlink{http://www.astrouw.edu.pl/cgi-asas/asas_lc/173742-4231.1}{173742-4231.1} \\
\hline
\end{tabular}
\end{center}
\end{table}
}

\clearpage

\begin{table}[!ht]
\begin{center}
{\normalsize Table 2. Fourier parameters for the new HADS.} \vskip2mm 
\begin{tabular}{ccccc}
\hline
GSC & $R_{21}$ & $\Phi_{21}$ & $R_{31}$ & $\Phi_{31}$ \\
\hline
7740-1289 & 0.37 $\pm$ 0.05 & 4.13 $\pm$ 0.16 & 0.20 $\pm$ 0.05 & 2.35 $\pm$ 0.18 \\
6698-0302 & 0.39 $\pm$ 0.01 & 4.08 $\pm$ 0.03 & 0.17 $\pm$ 0.01 & 2.29 $\pm$ 0.04 \\
9024-0007 & 0.39 $\pm$ 0.01 & 4.18 $\pm$ 0.04 & 0.18 $\pm$ 0.01 & 2.13 $\pm$ 0.08 \\
7892-1411 & 0.44 $\pm$ 0.01 & 4.03 $\pm$ 0.03 & 0.19 $\pm$ 0.01 & 1.76 $\pm$ 0.06 \\
\hline
\end{tabular}
\end{center}
\end{table}

{\bf Acknowledgements:} 
This research has utilised the ASAS3 public photometry catalogue.
It made use of data products from the Two Micron All Sky Survey, 
which is a joint project of the University of Massachusetts and the Infrared Processing 
and Analysis Center/California Institute of Technology, funded by the National Aeronautics 
and Space Administration and the National Science Foundation.
Use has been made as well of the SIMBAD and VizieR 
databases operated at the {\it Centre de Donn\'ees Astronomiques (Strasbourg)} in France and
the Guide 8 astronomical software package ({\tt http://www.projectpluto.com}).

\references

ESA, 1997, The Hipparcos and Tycho Catalogues, ESA SP--1200

Greaves, J., Wils, P., Van Cauteren, P., 2004, {\it IBVS}, No.\,5489

Hoffmeister, C., 1933, {\it AN}, {\bf 247}, 281

%H{\o}g, E., Fabricius, C., Makarov, V.V., Urban, S., Corbin, T., Wycoff, G., Bastian, U.,
%Schwekendiek, P., Wicenec, A., 2000, {\it A\&A}, {\bf 355}, L27

Morgan, S.M., 2003, {\it PASP}, {\bf 115}, 1250 ({\tt http://nitro9.earth.uni.edu/fourier/})

Pojmanski, G., 2002, {\it Acta Astronomica}, {\bf 52}, 397

Rodr\'\i guez, E., Breger, M., 2001, {\it A\&A}, {\bf 366}, 178

%Simon, N.R., 1986, {\it ApJ}, {\bf 311}, 305

Spencer, J.H., Jackson, J., 1939, His Majesty's Stationery Office, London, 
{\it Cape Catalog of 20554 Faint Stars, -40 to -52\deg} % \BIBCODE{1939HMSO..C......0S}

Strohmeier, W., 1967, {\it IBVS}, No.\,178

Zacharias, N., Urban, S., et al., 2003, {\it Second US Naval Observatory CCD Astrograph Catalog (UCAC2)}, in preparation

\endreferences


\IBVSfig{6cm}{5490-f1.eps}{ASAS3 phased light curve for GSC 7740-1289\vspace*{-1.5cm}}
\IBVSfigKey{5490-f1.eps}{GSC 8606-0190}{light curve}
\IBVSfig{6cm}{5490-f2.eps}{ASAS3 phased light curve for GSC 6698-0302 = NSV 6068\vspace*{-1.5cm}}
\IBVSfigKey{5490-f2.eps}{GSC 6666-0796}{light curve}
\IBVSfig{6cm}{5490-f3.eps}{ASAS3 phased light curve for GSC 9024-0007\vspace*{-1.5cm}}
\IBVSfigKey{5490-f3.eps}{GSC 7758-1126}{light curve}
\IBVSfig{6cm}{5490-f4.eps}{ASAS3 phased light curve for GSC 7892-1411 = NSV 9245\vspace*{-1.5cm}}
\IBVSfigKey{5490-f4.eps}{GSC 7892-1411}{light curve}

\end{document}

