COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 939

                                   Konkoly Observatory
                                   Budapest
                                   1974 October 25


       A NEW SOUTHERN FLARE STAR : CPD-72deg2640

   During the survey program on red dwarf variables (BY Dra stars)
that is being carried at ITA Observatory since 1971 (Ferraz  Mello
and Torres 1971) the star CPD-72deg2640 (CoD-72deg1700) was observed to
flare in 1973 July 30.
   This star was included in the survey after its classification
by Upgren et al. (1972) like a M2Ve star. The program was not 
specifically designed to obtain flare data of the included stars, so we
were not able to define a good light curve for the event (Fig. 1).

                       [FIGURE 1]

Nevertheless, it was a very intense one (at least 1m.4 in blue color,
and the flare nature of CPD-72deg2640 may be considered certain.


        IVO C. BUSKO               C.A. TORRES and G.R. QUAST
   Instituto Astronomico              Observatorio Nacional
        e Geofisico                  Rio de Janeiro - Brasil
    Sao Paulo - Brasil


References:
Ferraz Mello, S. and Torres, C.A., 1971 I.B.V.S. No. 577
Upgren, A.R., Grossengacher, R., Penhallow, W.S., MacConnell, D.J.,
        and Frye, R.L. 1972 Astronomical Journal 77, 486 [BIBCODE 1972AJ.....77..486U ]




                     FLARE ACTIVITY OF EQ Vir

   EQ Vir (HD118100, Sp K5Ve) was found to be a flare star by Ferraz
Mello (1972) and this was confirmed also by Chugainov (1973b).It is 
also a BY Dra star (Ferraz Mello and Torres, 1971), with the improved 
period of 3.958 days for 1971 observations. Nevertheless, EQ Vir may have
period variations like other BY Dra stars (Chugainov 1973a,b).
   In order to study the flare activity of EQ Vir, it was monitored
photoelectrically in the ultraviolet for a total of 11.9 hours, using
the 20 inch Cassegrain reflector of ITA Astronomical Observatory at Sao
Jose dos Campos (Brazil). The coverage is given in Table 1; all breaks
greater than 2 minutes are considered.

                              Table 1

Date 1974     Begin (UT) End       Date 1974       Begin (UT) End
 May 14     22h21m.9 - 24h00m.0      May 15      23h01m.7 - 24h00m.0
 May 15     00 00.0  - 00 53.4       May 16      00 00.0  - 00 49.8
            01 27.6  - 04 14.3       June 19     22 55.0  - 24 00.0
            21 34.9  - 22 59.1       June 20     00 00.0  - 02 21.4

   The time constant of the data system was always one second. Reduction 
methods used were the same as those described by Kunkel (1968, 1973).
   Only two events were observed, and the results are given in Table
2. They are, respectively: event U.T., U-magnitude of peak light after
subtraction of the quiescent component, flare duration at 0.5 peak light,
airmass, and the U-mag. of one standard deviation, measured prior to
the onset of the flare.

                              Table 2

     Event UT      U_{peak}     T_{0.5}     Airmass      U_{sigma}
    1974 May 15                 (min.)
     03h20m         11.80        9.7         1.23          14.0
     23 21.9        12.59        4.3         1.14          14.1

   In spite of low quality, the data at hand suggest a high activity
level of EQ Vir, possibly close to the upper limit for flare activity
found in solar neighborhood flare stars (Kunkel 1970).



          IVO C. BUSKO                   CARLOS A.O. TORRES
 Instituto Astronomico e Geofisico      Observatorio Nacional
 Universidade de Sao Paulo-Brazil      Rio de Janeiro - Brazil

References:

Chugainov, P.F. 1973a Izvestya Krymskoi Astrofizicheskoi Obs.v. 48, p. 3-22 [BIBCODE 1973IzKry..48....3C ]
Chugainov, P.F. 1973b Private communication
Ferraz Mello, S. 1972 I.A.U. Circular No. 2482 [BIBCODE 1973IAUC.2482....2F ]
Ferraz Mello, S. and Torres, C.A.O. 1971 I.B.V.S. No. 577
Kunkel, W.E. 1968 I.B.V.S. No. 315
Kunkel, W.E. 1970 P.A.S.P. 82, 1341 [BIBCODE 1970PASP...82.1341K ]
Kunkel, W.E. 1973 Ap.J. Suppl. 25, 1 [BIBCODE 1973ApJS...25....1K ]