COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 451


                                 Konkoly Observatory
                                 Budapest
                                 1970 July 17

                 YZ CANIS MINORIS

      Photoelectric monitoring of YZ CMi was carried out
at the Auckland Observatory with the 50 cm reflector. The
observations were made with an E.M.I. type 9502 photomultiplier 
tube and a standard B filter. The photometer
uses a capacitor integrating circuit to convert the photomultiplier 
current into a square wave pulse whose frequency
waves in proportion to intensity. This is monitored with a
digital frequency meter in ten second integrating periods.
      During 17 hours of monitoring three flares were
observed. Table 1 lists monitoring times with remarks on
seeing conditions. The details of observed flares are given
in Table 2.



                        Table 1.

Date    Monitoring time        Remarks
1970        U.T.    

Jan.31  1234-1245; 1331-1335    Haze.
        1414-1416.
Feb. 1  0946-0949; 0950-1032    Clouds and haze at beginning;
        1036-1115; 1123-1203    clearer for rest of night.
        1217-1244; 1247-1303
        1305-1322.
     2  1044-1115; 1117-1120;   Cirrus
     3  1147-1216; 1218-1227;   Passing clouds
        1259-1302; 1309-1324;
     4  0920-0936; 1038-1057;   Cloudy with clear patches
     5  0906-0911; 0936-0957;   Some cloud
        1013-1027; 1027-1037;   Clear
        1039-1104; 1125-1136;
        1140-1201; 1214-1243;
        1250-1345; 1413-1446;
        1454-1526; 1539-1552.
     6  1021-1056;              Cloudy.
        1104-1108; 1112-1126;   Clear
        1128-1146; 1148-1200;
        1209-1233; 1317-1319;   Cloudy
     7  1028-1045; 1046-1104;   Broken cloud
        1107-1116; 1258-1321;
        1325-1348.
     8  0944-0945; 0955-1025    Scattered cloud.
        1033-1100; 1111-1129;
        1130-1132; 1139-1153;   Clear
        1156-1200               Clear
        1246-1247               Cloud
    11  1128-1141               Cloud
        1248-1317; 1321-1335;   Clear
        1337-1351; 1357-1400;
        1405-1500; 1512-1523;




                       [FIGURE 1]


       Times of maxima are + 6 seconds. d_h= duration of
flare before maximum; d_a= duration of flare after maximum;
S.D. - Standard deviation near flare in B; Max. Mag.=
Intensity of max. in B as defined in IBVS 326; Integ.
Intensity = Integrated intensity, in minutes, as defined
in IBVS 326.
       The first two flares are depicted in Figures 1 and
2. The commencement of the third flare was not observed.


V.S.S. RASNZ            FRANK BATESON
18 Pooles Road          B.F. MARINO; W.S.G. WALKER
Greerton
Tauranga
New Zealand


                        Table 2.
                Observed flares of YZ CMi

Date    Max        d_b     d_a     S.D.    Max.         Integ.
                                           Mag.         Intensity
                                            B               
                                                        mins.

Febr.1  10h22m38s  <20^s   3m15s   0.023  >0.42         0.537
     6  11 13 35    23       45    0.027   0.19         0.080
     7  12 58 10     ?   >10mins   0.030  >0.34           -


                
                YZ CANIS MINORIS

      During the 1970 International period YZ CMi was
monitored visually by members of the Variable Star Section,
RASNZ., as under. No definite flares were observed.

                        
Date 1970               Monitoring times
  U.T.                       U.T.

Jan. 31                 09h08m - 09h18m
                        10 03  - 10 20
                        10 23  - 11 53
Feb.  1                 11 20  - 11 50
                        12 50  - 13 10
      2                 10 00  - 10 10
                        10 32  - 10 37
                        11 57  - 12 02
      3                 11 57  - 12 12
                        12 17  - 12 22
      4                 09 57  - 10 40
                        12 02  - 12 18
      5                 08 54  - 09 54
                        10 00  - 11 45
      6                 09 00  - 10 14
                        10 16  - 10 17
                        10 34  - 12 00
      9                 10 10  - 10 17
                        10 24  - 11 12
                        11 13  - 13 03
     10                 10 25  - 13 56

                           Total 15h08m

                                FRANK M. BATESON
                                Director,
                                Y.S.S., RASNZ

 18 Pooles Road
 Greerton
 Tauranga, New Zealand




             V 645 (PROXIMA) CENTAURI

     V 645 Cen was monitored at the West Melton
Observatory, Christchurch (N.Z.) with the 40 cm reflector.
The output of the photometer was recorded on tape. No
flares were observed.

1970 (U.T.)     Monitoring time
                   U.T.

May 31          0900 to 1200
June 10         1040 to 1130

                              FRANK M. BATESON
                              C. ROWE
                              R. AUSTIN
                              M. CLARK

V.S.S. RASNZ
18 Pooles Road
Greerton
Tauranga, New Zealand