COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                      NUMBER 678

                                      Konkoly Observatory
                                      Budapest
                                      1972 May 19


        PHOTOELECTRIC OBSERVATIONS OF V645 Cen


The flare star V645 (Proxima) Cen was monitored for a total of 9 hours 44
minutes on 5 nights in the period of cooperative observations 6-21 April,
1972 using the Auckland Observatory 50cm reflector. Observations were made
using the B filter of the Johnson UBV system, using an EMI 9502
photomultiplier tube and a digital recording apparatus with the exception of
the first two periods on April 10 when a V filter was used. The time
of monitoring is given in Table 1.

Table 1

                      Coverage UT

1972 April 9    0956-1007, 1011-1043, 1051-1247, 1258-1352.
          10    1025-1037, 1041-1052, 1112-1144, 1151-1205.
          13    1022-1029, 1036-1046, 1050-1121, 1126-1157,
                1203-1230.
          14    0725-0729, 0732-0818, 0902-0919, 0926-0957,
                1000-1019, 1021-1029.
          21    1031-1038, 1106-1140.

No definite flare activity was recorded.

Assistants: - G. Freeth, S. Clements, B. Wilde, P. Connolly, D. Paterson and
   F. Williams.

Auckland Observatory            B.F. MARINO and W.S.G. WALKER




                  THE U Gem TYPE VARIABLE Z Cha


The GCVS (1969) lists the photographic range of Z Cha as 12 - <13.5 with a mean
cycle of 66 days. During the interval 2,434,875 (1954 May 10) to 2,441,103
(1971 May 31) 59 maxima have been observed from 4,500 observations.

The mean cycle from these observations is 104.1 days with a visual range of
11.5 to <14.0. Maxima magnitudes range from 11.5 to 13.0. Maxima brighter
than 12.0 tend to reoccur at mean intervals of 343.5 days. The average number
of maxima of all types within any interval of one thousand days is 9.6 with
very little deviation.

The detailed results will appear in Memoir No 2, VSS, RASNZ.


                                  FRANK M. BATESON
VSS, RASNZ.




             VISUAL OBSERVATIONS OF YZ CMi AND V371 Ori


Visual observations of the flare stars YZ CMi and V371 Ori were carried out at
the Whakatane Observatory using their 20cm refractor. Coverage is given in
Table 1.

Table 1

Coverage UT

YZ CMi

1972 January 8 1149-1421, 1424-154.
             9 1144-1400
            10 1138-1418           Total 8h59m

V 371 Ori

1972 January 8 0938-1138
             9 0926-1136
            10 0855-1135           Total 6h50m

Four suspected flares of YZ CMi were observed at: - Jan. 9 13h09.5m; Jan. 10
11h57m; 12h21.5m and 12h42m. Each flare of 0.2 mag.

Suspected flares of V371 Ori were recorded at: - Jan. 8 10h08m (0.3mag);
11h28.5m (0.2mag); Jan. 9 10h15.5m (0.2mag).

Observers: - B. Marino; J. Duthie; J. McQueen.
VSS, RASNZ.


                                    FRANK M. BATESON