COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 432

                             Konkoly Observatory
                             Budapest
                             1970 April 21



                   AD Leo

      A continual photoelectric monitoring of the flare
star AD Leo was done with the 30 cm reflector of the Okayama
Station from 1 to 14 March 1970. During the 29 hours of
monitoring in the magnitude B, 2 flares were observed as
shown in the following table.




Date        Time of      Time of                     Duration
1970       Monitoring     max.        Flares                    sigma
March         (UT)        (UT)     m(B)      P                          
                                                                     mag
 1       12h38m-18h30m                 mag     min     min       0.08
 4       10 10 -12 29   11h03m9    0.33     0.5       3          0.07
         13 02 -14 24                                            0.06
         15 13 -16 18   15 25.4  > 2.5     >71       52          cloudy
         17 33 -18 24                                            0.07
 6       11 56 -17 07                                            0.06   
 7       10 20 -16 52                                            0.09
 8       11 53 -18 08                                            0.05
10       16 26 -17 45                                            cloudy

          The definition of m_f(B), P and sigma are as follows:

                 m_f(B) = m_0 - 2.5 log I_0+f/I_0

                 P = Integral (I_0+f - I_0)/I dt

                 sigma(mag) = 2.5 log (I_0+  )/I_0

			
Tokyo Astronomical Observatory
7 March 1970


                    K.OSAWA    K.ICHIMURA
                    T.NOGUCHI  E.WATANABE
                    T.OKADA    K.OKIDA