COMMISSION 27 OF THE I.A.U.
              INFORMATION BULLETIN ON VARIABLE STARS
                           Number 1287

                                                    Konkoly Observatory
                                                    Budapest
                                                    1977 May 31


    SEVEN-COLOUR PHOTOMETRY OF THE VARIABLE HD 25539

HD 25539 (alpha_1900 = 03h58.3m, delta_1900=32d18', B3V, V = 6.86) was
observed photoelectrically with the Geneva seven-colour photometer 
mounted at the 1m telescope of Observatoire de Lyon, at
Gornergrat Observatory, Switzerland, during 2 nights in
February 1977. The star was used as a comparison star for
X Persei (HD 24534). The other comparison star was HD 21856
(HR 1074, B1V, V = 5.9).
   From the high dispersions of the differential measurements
(Table 1) we conclude that one of both comparison stars is
variable on a timescale of several hours.


JD Hel.-
2440000  n    U       B       V       B1      B2     V1      G

201.39   3  0.030   0.011   0.010   0.013   0.010   0.005   0.009
203.33   8  0.018   0.004   0.007   0.004   0.005   0.003   0.005

Table 1. Standard deviations for the differential measurements
         HD 25539-HD 21856 for both nights. n denotes the
         number of measurements. The time indicated is a mean
         value for the whole night.

   From the standard deviations of the non-differential measurements 
in Table 2 we clearly see that HD 25539 is the variable.

Figure 1 gives the lightcurves resulting from the differential
measurements in the sense HD 25539-HD 21856 for both nights.
The differences are in the standard system of the photometer.


                        [FIGURE 1]



          HD 25539             HD 21856 (comparison star)

     JD 244    JD 244              JD 244     JD 244
     3201.39   3203.33             3201.39    3203.33

U    0.031     0.020              0.002       0.003
B    0.010     0.003              0.002       0.003
V    0.010     0.006              0.001       0.003
B1   0.011     0.004              0.004       0.004
B2   0.010     0.004              0.002       0.003
V1   0.005     0.002              0.001       0.002
G    0.010     0.004              0.002       0.003

Table 2.  Standard deviations of the non-differential
          measurements of HD 25539 and HD 21856 for both
          nights.

Acknowledgement

The authors wish to express their thanks to the Geneva and
Lyon observatories for the permission to use their equipment.


                              C. DE LOORE
                              C. STERKEN

                              ASTROPHYSICAL INSTITUTE
                              Vrije Universiteit Brussel
                              Pleinlaan 2
                              B-1050 Brussel





           Correction to I.B.V.S. No. 1269

   The third sentence ("Evidence has been found...") should
be omitted.

                                          E.C. OLSON