COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                              Number 2955

                                                         Konkoly Observatory
                                                         Budapest
                                                         13 November 1986

                                                         HU ISSN 0374 - 0676


 OPTICAL BEHAVIOUR OF THE POLAR ST LEONIS MINORIS = CW 1103 + 254 IN 1986

Using the sequence of comparison stars given in the IBVS No. 2735 the
star was measured on 20 blue-sensitive plates (ORWO ZU21 + GG13 + BG12).
from 14 nights taken with the 50/70/172 cm Schmidt camera of Sonneberg
Observatory covering the time interval between 7 February 1986 and 26 May
1986. On 6 nights more than one plate per night were obtained. The exposure
time of the plates amounts to 20 minutes. The individual observations are
listed in Table I.


                    Table I

J.D.hel.        m_B       J.D.hel.       m_B
244....                   244..

6469.586       15m41      6507.568      15m58
6469.606       15.59      6533.451      15.94
6473.590       15.36      6533.469      16.31
6473.609       14.96      6550.380      16.15
6474.512       15.44      6552.362      15.96
6474.531       15.03      6553.365      15.76
6476.550       15.33      6555.363      16.06
6476.572       15.07      6559.442      15.98
6506.546       15.70      6563.394      16.27
6506.566       15.93      6577.403      15.85


                           [FIGURE 1]
                           [FIGURE 2]


  The long time-scale light curve in B is shown in Figure 1.
There a slow decrease of brightness from m_B = ~15.2 to m_B = ~16.0 within the
given time interval can be seen. This behaviour can be explained as a decrease
from the X-ray heated high state of ST LMi to the mean brightness state, which
in former series of observations was accepted as the high state. From the
brightness distribution of the star obtained from all individual observations
between 1982 and 1986 and shown in Figure 2 the conclusion can be drawn that
the star prefers the mean brightness state. In connection with this behaviour
it is worth mentioning that in the season 1983/84 an increase of brightness
from the low to just the mean state was observed (Gotz, 1985).
   Because of the small number of observations in 1986 no positive statements 
about the behaviour of the occultation light changes can be made.


                             W. GOTZ

                   Akademie der Wissenschaften der DDR,
                    Zentralinstitut fur Astrophysik,
                        Sternwarte Sonneberg
                                DDR



Reference:

Gotz, W. 1985, I.B.V.S. No. 2735