COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      NUMBER 524


                               Konkoly Observatory
                               Budapest
                               1971 February 26


                     YZ CMi

	A photoelectric monitoring of the flare star YZ CMi
was done with the 91cm reflector of the Okayama Station
from 20 to 31 January 1971.
During the 34.5 hours of monitoring in the magnitude 
B, 20 flares were observed as shown in the  following
Table.


Delta m(B)  = 2.5 log (I_(0+f)_max / I_0)

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

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



Tokyo Astronomical Observatory
17 February 1971.




                           K. OSAWA
                           K. ICHIMURA
                           K. OKIDA
                           H. KOYANO




       Flares of YZ CMi observed at Okayama,
               20 to 31 January, 1971.
------------------------------------------------------------------------
Date       Time of          Time of Flares           Duration 
1971   Monitoring(UT)       max.(UT)  Deltam(B)   P              sigma
------------------------------------------------------------------------
Jan.                   
22     13h29m-15h20m       14h07.2m      0.14mag 0.2min   3min   0.05mag
       16 28 -19 07        18 00.4       0.64    2.3     11      0.05
23     10 46 -15 51        11 31.6       0.18    0.14     5      0.05
                           14 31.0       0.27    2.6     23      0.05
                           14 45.2       0.37
       16 05 -19 26
25     13 08 -19 10        14 36.4       0.44    1.3     23      0.05
                           16 10.6       0.26    0.5     12      0.04
                           17 35.8       0.29    0.3     10      0.04
27     10 08 -18 43        10 27.3       0.21    0.2      3      0.07
                           12 53.2       0.16    0.2      4      0.05
                           13 24.3       0.39    0.2      4      0.05
                           15 23.3       0.34|   1.1      5      0.04
                           15 24.4       0.85|
                           16.10.3       0.22    0.1      1      0.04
                           17 09.9       0.63    0.3      3      0.04
29     15 20 -16 07        15 35.1       0.61    1.7     13      0.03
30     10 25 -13 34        12 39.0       0.16    0.1      2      0.03
                           12 54.0       0.32    0.5      6      0.03
31     11 48 -12 20        11 49.3       0.12    0.2      2      0.04
       12 50 -13 20        13 01.3      >1.97  >20      >18    cloudy
       15 54 -16 04                                              0.05
       16 10 -16 37                                              0.05
       16 43 -17 40                                              0.05
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