COMMISSION 27 OF THE I.A.U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1585

                                Konkoly Observatory
                                Budapest
                                1979 April 16



          SOME INTENSE FLARES OF UV CETI


    Recent perusal of flare star records at Boyden observatory
revealed three intense outbursts from UV Ceti (R.A.=01h36m4,
declination = -18d13' (1950), visual magnitude 12,9 at minimum,
spectral type dM5,5e) hitherto unreported.
    The 41 cm Nishimura reflector was used for these observations, 
fitted with a Johnson B filter. The detector was an uncooled 
EMI 6256A photomultiplier tube.
    The flare of (I_0+f - I_0)/I_0 > 8,48 during the observational run
on the night of 14 - 15 September was confirmed visually in the
10 cm finder. Reductions from the photometer records were made
using a Hewlett Packard Model 9825 microcomputer and digitizer
and other computing facilities on the main campus of the Orange
Free State university.
    The flares reported showed the flash phase followed by
a more gradual decline characteristic of UV Ceti type flare
stars.
    The following table gives a summary of the observations:

--------------------------------------------------------------------------------
03/04 August 1975:      Monitoring Time: 00h40m08s- 03n00m27s U.T.

Flare maximum  (I_0+f - I_0)/I_0     2.5 log((I_0+f - I_0)/I_0)     sigma(mag)=-2.5log|sigma|/I_0     (m_lim - m_0)=sigma(mag)-1.19
  U.T.        
 01h48m15s            2.87                    1.15                                 1.76                            0.57



       Interruption in observing from:00h07m45s-00h12m45s U.T.

 22h58m10s           >8.48                  >2.32                                  2.45                            1.26
 23 11 32             2.19                   0.86                                  2.45                            1.26
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We wish to express our thanks to Prof. F.D.I. Hodgson, the
Director of the Institute of Groundwater Studies at the University, 
for access to his departments Hewlett Packard microcomputer.



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


                      [FIGURE 1]