COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       NUMBER 801

                                   Konkoly Observatory
                                   Budapest
                                   1973 June 4



PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR AD Leo DURING THE
     1973 JANUARY 27 - FEBRUARY 9 INTERNATIONAL PATROL




    Photoelectric observations of the flare star AD Leo have been
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 (Chugainov 1972).
    The preliminary results are here reported.

    In Table 1 the detailed coverage is given. During the 18.6
hours of observations two flares were detected. Their characteristics 
and light curves are given in Table 2, and in Figure 1, respectively.
   The explanation of the symbols and details, both on the observing 
equipment and on the reduction procedure are given in a preceding 
number of this Bulletin (Cristaldi S., Rodono M. 1971).


Astrophysical Observatory
citta universitaria
95125 Catania, Italy          S. CRISTALDI
May 20, 1973                  M. RODONO


References:
Chugainov, P.F. 1972. Comm. 27 IAU, I.B.V.S. No. 744.
Cristaldi, S., Rodono, M. 1971, Comm. 27 IAU, I.B.V.S. No. 525.



                       		Table 1

                   	 Detailed Coverage
                                                           Total        ________
Date   Tel. Light         Coverage(UT)                    coverage      3sigma/I_0
Jan.
30-31  61   U/B/V    21h30m-2146;2149-2218;2227-2230;      335        .04/.02/.02
                     2232-2249;2254-0115;0130-0141;
                     0157-0336;0347-0406.
Feb.
6-7    61   U/B/V   2037-2114;2125-2346;0025-0121;
                    0134-0149;0156-0159;0202-0239;
                    0248-0431.                             392        .17/.02/.02
Feb.
7-8    61   U/B/V   2041-2306;2309-2327;2330-2345;
                    2348-0034;0036-0057;0100-0153;
                    0155-0224;0225-0252;0256-0430;
                    0432-0444.                             460        .11/.02/.02
Feb.
8-9    61   U/B/V   2051-2123;2137-2146;2149-2200;
                    2237-2242;2246-2253;2256-2314;
                    2316-2324;2327-2339;2342-2351;
                    2354-2359;0007-0009;0113-0116;
                    0156-0207;0210-0213;0217-0231;
                    0233-0246;0301-0440.                   261        .09/.04/.02



                      		 Table 2

	                  Flare Characteristics



No.Tel.Light tmax(UT)  J.D. db  da 3sigma/I_or(I_f/I_o)max P Energy  Air  f    sky
    								erg  mass                  
               Feb. 1973
1  61 u 7; 02h02m60 1720.5905 1.5 9.8 0.12 0.53 1.56  		     1.16  0    0
      b       02.60           0.3 0.1 0.03 0.08 0.02
      v       (not detectable)        0.02 0.02 0.00
      U                   	      0.49 1.44 9.2x10^30
      B                               0.07 0.01 5.9x10^29
2(b)61u 8;23 46.70  1722.4961 0.8  -  0.15 1.93 17.23                1.03 3-4-5  0
 (d)  b   23 50.05            1.0  -  0.03 0.42 3.87
 (d)  v   23 50.50            1.5  -  0.02 0.16 1.44 
      U                                    1.76 16.02 1.0x10^32
      B                                    0.38 3.56  1.6x10^32
      V                                    0.13 1.17  1.1x10^32


                        [FIGURE 1]