COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       NUMBER 550

                                  Konkoly Observatory
                                  Budapest
                                  1971 May 20

PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR AD Leo, DURING
    THE 1971 FEBRUARY 18 - MARCH 4 INTERNATIONAL PATROL

      The preliminary results of AD Leo photoelectric observations carried 
out at the stellar station of the Catania Astrophysical Observatory 
according to the observing schedule proposed by the IAU Working Group on Flare
Stars (Andrews, et al. 1971 ) are here reported.
      In Table 1 the detailed coverage is given. During the 4.8 hours of
observations no flare activity was detected.


Table 1                     Detailed coverage
-----------------------------------------------------------------------------
Date
of        Tel.    Light     Coverage (U.T.)           Total    3sigma/I_0
observation                                           coverage  
-----------------------------------------------------------------------------
1971
Feb.22    91      b         01h17m 0155; 0157-0241;
                            0255-0303; 0320-0407;
                            0426-0442                 153m      0.03
"26-27    61/3c   u'-b-v    2131-2144; 2148-2153;
                            0042-0046; 0048-0055;
                            0057-0106; 0110-0112;
                            0115-0130; 0133-0138;
                            0144-0159; 0203-0207;
                            0210-0227; 0315-0325;               0.03(u')
                            0327-0330; 0332-0339;               0.01(b)
                            0343-0348; 0351-0355;     136       0.01(v)
                            0358-0409
-----------------------------------------------------------------------------



The explanations of symbols used and details of the observing
equipment can be found in a preceeding Bulletin (Cristaldi and Rodono, 1971).


Catania Astrophysical Observatory, Italy  S. CRISTALDI and M. RODONO


References
Andrews, A. D., Chugainov, P. F., Kellogg, E. M., Oskanian, V. S. 1971,
             Comm. 27 IAU, Inf. Bull. Var. Stars No. 516

Cristaldi, S., Rodono M. 1971, Comm. 27 IAU, Inf. Bull. Var. Stars No. 525