COMMISSIONS 27 AND 42 OF THE IAU
             INFORMATION BULLETIN ON VARIABLE STARS
                         Number 3938

                                            Konkoly Observatory
                                            Budapest
                                            23 September 1993

                                            HU ISSN 0374 - 0676


               CHANGES IN THE LIGHT CURVES OF AP LEONIS

 AP Leo is an over-contact binary system (Zhang et al., 1992). Its light curves showed
large changes in the past ten years. Photoelectric observations were carried out by us in
1983, 1984, 1985, 1988 (Zhang et al., 1989), 1990, 1991 and 1993 seasons. Six annual BV
light curves were obtained. We present three light curves observed in 1985, 1991 and 1993
as shown in Figures 1-3.
 Table I lists the minimum times observed in the nineties.

                  Table I
         New light minima for AP Leo
--------------------------------------------
J.D.(Hel)V  M.E.     J.D(Hel)B    M.E.   Min
2440000+             2440000+
--------------------------------------------
7925.2716   0.0020   7925.2723   0.0017   II
7928.2856   0.0006   7928.2867   0.0005   II
8310.2278   0.0005   8310.2284   0.0004   I
8311.3031   0.0003   8311.3033   0.0005   II
9037.0988   0.0005   9037.0980   0.0007   I
9037.3107   0.0002   9037.3117   0.0004   II
--------------------------------------------

                           [FIGURE 1]

       Figure 1.   The light curve of AP Leo in 1985.

                           [FIGURE 2]

       Figure 2.   The light curve of AP Leo in 1991.

                           [FIGURE 3]

       Figure 3.   The light curve of AP Leo in 1993.

 It is found that the depth of the primary minima of AP Leo changes as shown in
Table II.

                    Table II
          
                Eclipse depth of AP Leo
      -------------------------------------------------  
      Amplitude     1985  M.E. 1991  M.E  1993 M.E.
      -------------------------------------------------
      V Min(I)-Max  0.54  0.01 0.63  0.01 0.59 0.02
      V Min(II)-Max 0.53  0.01 0.54  0.01 0.53 0.02
      B Min(I)-Max  0.58  0.01 0.67  0.01 0.64 0.01
      B Min(II)-Max 0.58  0.01 0.56  0.01 0.56 0.01
      -------------------------------------------------

  The detailed analysis will be published in a forthcoming paper.


                          ZHANG Ji-tong
                          ZHANG Rong-xian
                          Beijing Observatory
                          The Chinese Academy of Sciences
                          Beijing, China 100080



References:

Zhang, J. T., Zhang, R. X., Zhai, D. S., Li, Q. S., Jin, T. L., 1989, IBVS, No. 3302
Zhang, J. T., Zhang, R. X. et al., 1992, Acta Astronomica Sinica, 33, 131 [BIBCODE 1992AcASn..33..131Z ]