COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 399


                              Konkoly Observatory
                              Budapest
                              1969 November 4




                   EV LAC


      A continual photoelectric monitoring of the flare
star EV Lac was done with the 91-cm reflector of the Okayama
Station in the period from 2 to 19 September 1969. During
the 33 hours of monitoring in the magnitude B, 12 flares
were observed as shown in the following table. By the 
observations, the sum of the light of EV Lac and its optical
companion was measured. The values of m_f (B), P and sigma in the
table are the results corrected for this companion. The
magnitude difference between EV Lac and the companion was
assumed to be 0.91 magnitudes according to the Information
Bulletin No. 370.
      The definition of m_f (B), P and sigma are as follows:

          m_f = m_0 - 2.5 log I_0+f/I_0
          P   = (I_0+f-I_0)/I_0  dt,
          sigma (mag) = 2.5 log (I_0+sigma)/I_0.



Tokyo Astronomical Observatory
30 October 1969


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


     Flares of EV Lac observed at Okayama,
     2 to 19 September, 1969.

Date
1969      Time of	 Time of   m_f(B) P Duration   sigma
Sept.  monitoring (UT)  max.(U.T.)                      mag
 2    13h34m-13h56m                                    0.06
 4    12 01 -13 00                                     0.04
      13 17 -14 04                                     0.07
 5    15 19 -15 54                                    cloudy
      16 36 -16 54                mag    min           0.07
      17 08 -18 27      18h21.0m  0.28  0.36  2.1min   0.07
 6    13 13 -14 10                                     0.07
      14 31 -14 49                                     0.07
 7    13 14 -13 33                                    cloudy
 8    11 57 -12 30                                     0.07
11    12 43 -13 00                                     0.07
12    10 23 -18 50      17 31.8   0.28   0.24 2.0      0.04
15    12 10 -17 00      13 45.8  >0.9   >0.8 >2.6     cloudy
                        15 50.8  >0.9   >1.5 >3.4     cloudy
16    10 27-11 02                                      0.08
17    11 52-12 00                                      0.04
      12 07-12 20                                      0.04
      12 54-13 17                                      0.04
      14 01-14 16       14 09.5   0.15   0.07 0.9      0.04
      14 54-15 10                                      0.04
      15 13-15 34                                      0.04
      15 50-16 05                                      0.04
      16 17-16 28                                      0.04
      16 35-19 15       18 14.1   0.28   0.24 3.7      0.04
                        18 24.3   0.20   0.07 0.8      0.04
18    10 23-15 30       11 26.1   0.08   0.04 2.5      0.03
                        11 28.8   0.13   0.03 2.5      0.03
                        12 48.9   0.10   0.19 3.3      0.03
                        15 12.2   0.28   0.09 1.3      0.03
19    10 40-14 12       12 20.5   0.33   0.23 4.2      0.04





                    [From IBVS 410]

Correction to IBVS 399: For Sept. 15 the time of maximum
                        should be read 17h01m8 (instead of
                        17h31m8).