COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1621

                                   Konkoly Observatory
                                   Budapest
                                   1979 June 12




        FAINT VARIABLE IN THE FIELD OF NGC 6397




   There has been renewed interest recently in the incidence of close
binary systems in globular clusters (see, for example, Niss et al. 1978;
Liller, 1978, Alexander and Budding, 1979). Motivated by this interest,
10 plates of the relatively near (~ 2kpc) globular cluster NGC 6397 were
taken last year with the 74" reflector at Sutherland. A few plates were also
received from other sources. Numerous examples of suspicious objects
were subsequently found, but no very convincing cases of variability
of the sought type have been discovered so far. A fuller presentation of
this work will be given elsewhere.
   The main purpose of the present note is to call attention to one of the
more prominent variables which was recently picked up in the cluster halo.
Its position is indicated on the accompanying chart. Details of its magnitude
variation on the 10 Sutherland plates are given below. Cannon's (1974)
sequence was used in calibrating the iris photometer readings and, to the
accuracy of the determination ( ~ 0.05m), it is regarded that the 
arrangement                    
of filters and emulsions used corresponds to standard B and V.
   With the apparent tendency to faintness it seems unlikely that the
variable could be a close binary system; in any case, its magnitude would
probably make it too bright to be a binary of the sought type. However, it
may be interesting to trace the variable on other plates and determine any
periodicity. In connection with this work we would like to remark that any
long exposure plates or film copies of such plates of NGC 6397 which could
be sent to the authors would be gratefully received.


                              [FIGURE 1]


J. D.244+   Magnitude   J. D. 244+   Magnitude
3603.542    16.47 B     3608.664     15.83 B
3603.635    16.10 V     3609.550     16.50 B
3607.519    16.38 B     3609.588     16.35 B
3608.571    15.64 B     3609.641     16.52 B
3608.616    16.12 B     3609.667     16.47 B





                           E. BUDDING
                           C. HENSHAW
                           Department of Astronomy,
                           University of Manchester,
                           Manchester.
                           M13 9PL





References :

Alexander, M. E., Budding, E.: 1979, Astron. Astrophys. 73, 227 [BIBCODE 1979A&A....73..227A ]
Cannon, R. D.: 1974, Mon. Not. R. Ast. Soc., 167, 557 [BIBCODE 1974MNRAS.167..551C ]
Liller, M. H.: 1978, I.B.V.S. No. 1527
Niss, B., Jorgensen, H. E., Lausten, S.: 1978, Astron. Astrophys. Suppl.
  32, 387 [BIBCODE 1978A&AS...32..387N ]