COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      NUMBER 767

                                       Konkoly Observatory
                                       Budapest
                                       1973 February 12

PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR YZ CMi DURING THE
   1972-73 30 DECEMBER - 12 JANUARY INTERNATIONAL PATROL.



    The preliminary results of YZ CMi photoelectric observations
carried out at the Catania Astrophysical Observatory during the
observing period proposed by the IAU Working Group on Flare Stars
(Chugainov P.F. 1972, IBVS 744) are given.
    The observations were made in b light with a 91 cm cassegrain
type reflector feeding a classical one-channel photoelectric 
photometer and with a 61 cm universal type reflector feeding a 
synchronous u, b, v photometer.
    The detailed coverage intervals are given in the accompaniing
Table 1.
    Only one flare was detected during the 3.5h patrol. The 
characteristics of the observed flare are reported in Table 2 and the
light curve is given in the Figure.
    The explanation of symbols and details of the observing equipment 
can be found in a preceding number of this Bulletin (Cristaldi
S., Rodono M., 1971, IBVS 525).



Catania Astrophysical Observatory,
Italy
January 31, 1973


                        S. CRISTALDI and M. RODONO



                                Table 1
                           Detailed Coverage
------------------------------------------------------------------------
Date Tel. Light               Coverage(U.T.)             Total 3sigma/I_0
                                                     coverage           
------------------------------------------------------------------------
110173 91 B   2345-2400; 0000-0009; 0025-0134; 0147-0201;
              0209-0214; 0224-0233; 0245-0330; 0334-0419. 211  0.07
120173 61 B/V 2221-2226; 0006-0017; 0031-0039; 0056-0100;
              0106-0112; 0116-0143; 0147-0319; 0325-0408;
              0420-0428.                                  204 /.16/.10
------------------------------------------------------------------------




                   Table 2
----------------------------------------------------------------
              Flare characteristics
Date(UT): 1973 Jan. 12, 02h45.9m (JD_hel 2441694.6206)
----------------------------------------------------------------
d_b   = 0.17m      3sigma/I_0 = 0.07      P = 0.15  1.90x10^30er
d_a   = 0.82m   (I_f/I_0)_max = 0.49      Air mass = 1.54
----------------------------------------------------------------

Sky : some cirrus, moonless


                        [FIGURE 1]