COMMISSION 27 OF THE I. A. U.
               INFORMATION BULLETIN ON VARIABLE STARS
                           Number 3515

                                                    Konkoly Observatory
                                                    Budapest
                                                    10 September 1990

                                                    HU ISSN 0374 - 0676


   SEARCH FOR SLOW LIGHT VARIATIONS OF RED DWARF STARS. II

Eight active late-type dwarfs were studied for long-term
variability in the mean light using the Sternberg Institute plate
collection by the method published in [1]. The yearly mean light for
the investigated stars and their comparison stars are shown in
Figures 1 and 2. The vertical bars in Figures represent standard
deviations of single measurement from yearly mean as it has been
made in [2]. The total number of plates for each star is given in
Figures. The measurement errors were not larger than 0.07m and the
light variations with amplitude more 0.2m can be suggested as real.
The stars in Figure 1 - CU Cnc, CV Cnc, and V780 Tau - showed such
variations. On the light curves of these stars one can see the
smooth changes or decreases in some time intervals of about 10 or
more years with amplitudes up to 0.3m. The large scatter in several
years indicates the short-term variations during the year. For V780
Tau the amplitude of such variations exceeds 0.5m.
   All stars in Figure 2 did not show the visible variability in
mean light. But the mean light for only one star - OU Gem - can be
considered as constant with confidence. For the other stars the data
are scanty and additional investigations are needed.


                           [FIGURE 1]

 Fig.1. The mean light curves for the stars with suspected variability

                           [FIGURE 2]

 Fig.2. The mean light curves for the stars with no certain variability


                                              N.I. BONDAR'
                                   Crimean Astrophysical Observatory
                                        Nauchny, Crimea, 334413
                                                  USSR


REFERENCES

1. Bondar', N.I. 1990, in Flare stars in star clusters, associations
and the solar vicinity, eds. L.V. Mirzoyan and B.R. Pettersen
(Reidel, Dordrecht), in press [BIBCODE 1990IAUS..137...55B ]
2. Phillips, M.J., and Hartmann, L. 1978, Astrophys. Journal, 224, 182-184. [BIBCODE 1978ApJ...224..182P ]


                          [From IBVS 3598]
                                   
                               ERRATUM
 
 
   In the No. 3515 issue of the IBVS, in Figure 2 the lowest panel shows
the magnitudes of HK Aqr (Gl 890). The star name HR Aqr is erroneously
drawn in the Figure.
 
                                                N.I. BONDAR'