COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 554


                                    Konkoly Observatory
                                    Budapest
                                    1971 May 24

PHOTOELECTRIC OBSERVATIONS OF THE FLARE STAR YZ CMi DURING
   THE 1971 JANUARY 16 - FEBRUARY 2 INTERNATIONAL PATROL

      The preliminary results of YZ CMi photoelectric observations
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 (Andrews, et al. 1971), are here presented.


                               Table 1
                          Detailed coverage
-----------------------------------------------------------------------------
Date Tel.    Light     Coverage (U.T.)                Total        3sigma/I_o
                                                     coverage   
-----------------------------------------------------------------------------
1971
Jan. 61/3c   u'-b-v    20h26m-2042; 2044-2109; 2111-
27-28                  2117;
                       2129-2158; 2204-2216; 2237-2301;
                       2303-2316; 2318-2330; 2332-2345;
                       2347-2400; 0000-0001; 0003-0019;            0.15(u')
                       0021-0037; 0039-0130; 0133-0149;            0.15(u')
                       0151-0211                       283m        0.02(v)
28-29 "      u'-b-v    2157-2209; 2212-2221; 2231-2303;            0.16(u')
                       2305-2332; 2335-2400; 0000-0149;            0.02(b)
                       0154-0108                       228         0.01(v)
Feb.
12-13 "      b-v    1950-2001; 2008-2017; 2028-2039;
                    2044-2101; 2104-2116; 2122-2135;
                    2213-2224; 2314-2318; 2327-2336;
                    2341-2353; 2356-2400; 0000-0004;               0.14(b)
                    0012-0023; 0026-0030                132        0.04(v)
22      91 b        2239-2310                           031
Mar.
20      61 u'-b-v   1926-1936; 1952-2005; 2007-2020;
                    2024-2040; 2101-2115; 2117-2139;
                    2145-2153; 2200-2211; 2222-2240;               0.10(u')
                    2250-2256; 2304-2311; 2317-2326;               0.02(b)
                    2330-2337                           154        0.02(v)
------------------------------------------------------------------------------





    Table 2 Characteristics of Observed Flare (Tel.61 cm)
---------------------------------------------------------------------------
Light t_max (U.T.)               3sigma/I_0                  P     Air  sky
max                    d_b   d_a           (I_f / I_0)_max         mass
---------------------------------------------------------------------------
u'     1971             -     -     0.17        -             -    1.10   0
b      Jan.29          0.8  35.5    0.03       3.31          7.44  1.10   0
       00h04m.4
v      00 04 .3        0.5  28.8    0.02       0.79          2.00  1.10   0
---------------------------------------------------------------------------




In Table 1 the detailed coverage and in Table 2 the characteristics
of the observed flare are given, The w, b and v light curves of the observed
flare are shown in Figure 1.
	The explanations of symbols used and details of the observing
equipment can be found in a preceeding number of this Bulletin (Cristaldi and
Rodono, 1971).

Catania Astrophysical Observatory, Italy
May 5, 1971

                           S. CRISTALDI and M. RODONO'

References

Andrews, A. D., Chugainov, P, F., Kellogg, E. M., Oskanian, V. S. 1971,
      Comm. 27 IAU, Inf. Bull. var. Stars No. 516

Cristaldi, S., Rodono, M. 1971, Comm. 27 IAU Inf. Bull. var. Stars No. 525



                         [FIGURE 1]