COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 3045


                                    Konkoly Observatory
                                    Budapest
                                    7 July 1987

                                    HU ISSN 0374-0676



 OPTICAL BEHAVIOUR OF THE X-RAY SOURCE EXO 020528+1454.8
                IN THE SEASON 1986/87


   This object consisting of a pair of dMe stars (dM4.5e+dM4.5e)
is identical with Lowell's proper motion star G035-027. First
results about the optical behaviour were given by Hudec et al,
(1986).


                       [FIGURE 1]


  In linking to the sequence of comparison stars given in
Figure 1 and Table I the object was measured on 84 blue-sensitive 
plates (ORWO-ZU21+GG13+BG12) from 26 nights obtained with
the 50/70/172 cm Schmidt camera of Sonneberg Obaervatory covering
the time interval between August 2, 1986 and February 23, 1987.
The magnitudes in B of the comparison stars listed in Table I
are linked to the sequence of comparison stars of TT Arietis
given by Gotz (1985). The star "h" there is identical with the
star "x" in the present sequence.
  The magnitude distribution in B of all individual observations 
is shown in Figure 2. Most of them are in the range between 
mB = 15.65m and mB = 16.05m. There is no doubt that the
object is variable. But its variability, caused by the two
components, is of low amplitude and belongs probably to the low
and quiet state of the stars.
  In series of 5 and more plates per night the individual
observations are scattering within Delta mB =/~ 0.3m. Only in the night
of J.D. 244 6763 the amplitude amounts to Delta mB =/~ 0.5m.

                   Table I

           comparison     mB
             star

              x 	14m86
              a	 	15.64
              c 	15.89
              d 	16.30
              e 	16.84


                         [FIGURE 2]
                         [FIGURE 3]


  No flare was observed, as can be seen from Figure 3, where
the mean values of brightness from each night are given to show
the long-scale behaviour of the object.



                               W. GOTZ
                   Akademie der Wissenschaften der DDR,
                   Zentralinstitut fur Astrophysik,
                   Sternwarte Sonneberg, DDR



References:
Gotz, W., 1985, Inf. Bull. Var. Stars No. 2823
Hudec, R., Wenzel, W., Gotz, W., Valnicek, B., Peresty, R., Richter, G.A.,
    Hacke, G., Huth, H., Mrkos, A. and Tremko, J., 1987, Proc. IAU
    Colloquium No. 93, Astrophys. Sp. Sci. 131, 697 [BIBCODE 1987Ap&SS.131..697H ]