COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                   Number 1641

                                 Konkoly Observatory
                                 Budapest
                                 1979 July 17



             OBSERVATIONS OF V645 Cen



     During April 1976 the flare star V645 Cen (R.A. 14h26m42s,
declination - 62d29' /1950/, 11.3 visual magnitude at minimum,
spectral type dM5e) was monitored during three nights at Boyden
Observatory.
     An uncooled EMI 6256A photomultiplier tube and a standard
Johnson B filter were used, fitted to the 41 cm Nishimura reflector. 
Observing conditions were excellent throughout the runs.
     Seven low intensity flares were recorded, five being 
considered as spike flares following Moffett's terminology (1).
     The diagrams are representative of the flares; they are 
similar in character to some of the V645 Cen flares we have observed 
on previous occassions.

Date       Monitoring  Time of Flare  (I_0+f - I_0)/I_0  Duration of    Comments
           Time (U.T.) Maximum (U.T.)                    Flare (seconds)

06 April   17h54m00s   19h23m36s              0.82              6         Small flare
1976       to
           19 33 00
23 April   19 20 45    21 23 37               1.06              3         Spike flare
1976       to          21 56 51               0.71              3         Spike complex
           23 20 00    22 35 28               0.56              4         Spike flare
                       22 38 03               0.61              3         Spike flare
24/25 April
1976       23 35 00    00 51 53               1.19              2         Spike flare
           to          02 26 14               0.91            >78         flare
           03 20 13

     We are greatly appreciative of the help given to us by
Professor F.D.I. Hodgson, the Director of the Institute of Groundwater 
Studies at the university, in providing access to his 
department's Hewlett Packard Model 9825 microcomputer and digitizer
for the reduction of our data.

                     A.H. JARRETT and J. VAN ROOYEN
                     Boyden Observatory
                     Astronomy Department
                     University of the Orange Free State
                     Bloemfontein, Rep. of South Africa


Reference:
(1) Moffett, T.J., 1974, Sky and Telescope, 48. 94 [BIBCODE 1974S&T....48...94M ]


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