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\IBVShead{4296}{9 February 1996}                      % Use it with dummy or empty arguments

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\title{New Possible Variables in the Globular Cluster NGC\,6229}

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        We present a list of 12 new possible variable stars in the core
of the halo globular cluster NGC\,6229.

        The Third Catalog of Globular Clusters (Sawyer Hogg, 1973) lists 22
variable stars in this cluster. One of them is  Population II cepheid,
others are RR Lyrae type variables.

        In order to search for not yet detected variables the method proposed
by Kadla and Gerashchenko (1982) was used. It is based on an analysis of a
color-magnitude diagram obtained from measurements of two images taken
``simultaneously". Thus the variables are at identical phase and the RR Lyrae
stars are located in the RR Lyrae gap.
       
 We have at our disposal two pairs of CCD images in B and V
colors covering the central $1.5\,\times\,1.2$ arcmin of the cluster
taken with SBIG ST-6 CCD camera attached at the 2 meter
telescope in NAO ``Rozhen", kindly granted by ESO. The scale is 0.32
arcsec/pixel.
In the central part of the cluster the crowding prevented
accurate photometry. However, by using the positions of stars determined
from frames after noise suppression, through wavelet transform (details
will be reported elsewhere) we were able to obtain reasonable photometry
at 1.5 mag below the HB.
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\centerline{Table 1. Possible variable stars in the core of NGC\,6229}
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\centerline{NGC\,6229: $\alpha$ = 16\fh 45\fm 6 $\delta$ = +47\degr 37'}
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\begin{tabular}{crrccc}
\hline\\

 Number        &X\ \ \ \ \ &Y\ \ \ \ \ & V  &B\,$-$\,V & R \\
               & (arcsec) &(arcsec)& &       & (arcmin) \\[2mm]
\hline\\

     1     & $-$7.30   & $-$4.09   &18.47  & 0.46  & 0.13\\
     2     & $-$2.55   &  12.62   &18.18  & 0.45  & 0.20\\
     3     &   4.64   & $-$3.86   &17.90  & 0.36  & 0.20\\
     4     &  11.54   &  6.94    &17.29  & 0.34  & 0.21\\
     5     &   7.76   & $-$10.29  &18.56  & 0.44  & 0.24\\
     6     & $-$0.91   & $-$15.71  &18.40  & 0.34  & 0.29\\
     7     &   7.77   & $-$16.83  &17.57  & 0.15  & 0.34\\
     8     &  $-$4.03  & $-$21.29  &18.12  & 0.45  & 0.40\\
     9     &  $-$7.10  &  23.69   &18.22  & 0.43  & 0.40\\
     10    &  27.49   &   5.46   &18.17  & 0.44  & 0.44\\
     11    &  28.72   &  17.97   &18.18  & 0.42  & 0.54\\
     12    & $-$22.02  &  24.35   &18.18  & 0.42  & 0.52\\
\hline
\end{tabular}
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\centerline{Figure 1}
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        Among the 22 known variables in the cluster 8 were detected
on our frames because of our small field of view:
V5, V6, V8, V11, V12, V15, V16 and V20.

        12 new suspected variables have been found and information of them
is given in Table 1.
In columns 2 and 3  of Table 1 the coordinates in arcsec
of the new possible variables in the Sawyer Hogg (1973) system are listed.
The next two columns contain V and B$-$V values, determined by only
one image pair.
R is the projected radial distance in arcmin from the cluster center.

        This research was supported by the Bulgarian National Scientific
Foundation grant under contract No F-328/1993 with the Bulgarian Ministry
of Education and Sciences.



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\authorsrightcol
N. SPASSOVA and J. BORISSOVA
Institute of Astronomy
Bulgarian Academy of Sciences
72~Tzarigradsko shosse
BG\,--\,1784 Sofia
Bulgaria
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\references

Kadla, Z., Gerashchenko, A., 1982 ,Inv. Main A. O.
of the Academy of USSR (Pulkovo), {\bf 199}, 86

Sawyer-Hogg, H.: 1973, Publ. David Dunlap Obs., 3, No.\,6


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