COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     Number 759


                                   Konkoly Observatory
                                   Budapest
                                   1973 January 23


        PHOTOELECTRIC OBSERVATIONS OF EV LAC
   DURING THE 1972, SEPTEMBER 1-15 INTERNATIONAL PATROL


    According to the observing schedule of cooperative 
observations proposed by the IAU Working Group on flare stars
(P.F. Chugainov 1971, IBVS No. 605), EV Lac was patrolled at
the Catania Astrophysical Observatory for about 17.5 hours.
The observations were carried out with a 61 cm universal type
reflector feeding a synchronous u, b, v photometer.
    The detailed coverage intervals are given in Table 1.
Three flares have been observed and their characteristics
are reported in Table 2. The light curves of the observed
flares in U, B, V are shown in figures 1, 2 and 3.
    The explanation of symbols and details both on the 
observing equipment and on the Catania photometric system can
be found on Cristaldi S. and Rodono M., Astron. and Astrophys. 
Suppl. 10, 1973.
    M. Consoli, C. Lo Presti, F. Spinella have collaborated
to the present work.


Catania Astrophysical Observatory
December 29, 1972

                           S. CRISTALDI
                           M. RODONO




                       Table 1
-------------------------------------------------------------------------
Date     Tel.  Light             Coverage(U.T.)        Total   3sigma/I_0
1972                                                  coverage
-------------------------------------------------------------------------
 1  Sep.  61   u,b,v   0000-0006; 0105-0143.            139 .16/.05/.03
 3   "    61   u,b,v   2349-2400; 0000-0037; 0040-0302. 190 .16/.04/.03
 9   "    61   u,b,v   2030-2050; 2052-2117; 2142-2215;
                       2218-2230; 2231-2254; 2255-2400;
                       0000-0007; 0010-0015; 0017-0103;
                       0142-0236; 0243-0259.            296 .17/.04/.03
10   "    61   u,b,v   2028-2057; 2124-2139; 2145-2229;
                       2230-2327; 0124-0226.            209 .19/.04/.03
12   "    61   u,b,v   1925-1950; 1952-2056; 2110-2132;
                       2141-2258; 2300-2337; 2339-2400;
                       0000-0003; 0008-0036.            217 .20/.07/.04
-------------------------------------------------------------------------




                       Table 2
------------------------------------------------------------------------------------------------
                           JD
No. Tel. Light t_maxU.T. 244157. d_b  d_a 3sigma/I_0  I_fmax/I_0    Energy          Air    f sky
               1972 Sep.                                           P     erg        mass
------------------------------------------------------------------------------------------------
1   61    U   11.235740          0.3  9.2   0.37        9.25     15.60  4.00x10^31         0
          B      235730 2.5020   0.2  9.3   0.09        1.38      2.89  6.35x10^31  0.860  0 1
          V      235740          0.1  5.9   0.04        0.41      0.51  2.52x10^31         0
2   61    U   12.024760          0.6 15.9   0.39        2.35     11.64  3.68x10^31         0
          B      024790 2.6205   0.2  3.9   0.09        0.54      1.23  2.71x10^31  1.270  0 1
          V      024810          1.0  1.7   0.05        0.12      0.27  1.36x10^31         0
3   61    U   12.214690          1.0  8.6   0.56        3.51      7.64  2.41x10^31         0
          R      214650 3.4113   1.3  4.0   0.12        0.56      1.80  3.97x10^31  0.820  0 1
          V      214660          1.5  0.6   0.05        0.15      0.06  0.29x10^31         0
------------------------------------------------------------------------------------------------


                         [FIGURE 1]
                         [FIGURE 2]
                         [FIGURE 3]