COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                         Number 923

                                      Konkoly Observatory
                                      Budapest
                                      1974 September 7


               ON THE BEAT PERIOD OF AE UMa *

   AE Ursae Majoris has been found recently by V.P. Tsessevich (1)
to be a dwarf Cepheid variable. Tsessevich noted also that the light
curve varies strongly.
   Some hundreds B and V photoelectric measures obtained at the
Merate Observatory during the first months of 1974 give evidence of
a beat phenomenon in the light curves. A nine hours observing run
is reported in the figure. It appeared evident there was a remarkable 
variation in the light maxima, which can reach two tenths of
magnitude from one maximum to the next. A preliminary analysis of
our observations confirms the fundamental period given by Tsessevich:
P_0 = 0d.087017 and displays a beat phenomenon whose period is 
approximately: P_b = 0d.294.

                        [FIGURE 1]

                                   P. BROGLIA, P. CONCONI
Merate August 26, 1974.

(1) Tsessevich V.P., 1973, Astron. Circ. 775. [BIBCODE 1973ATsir.775....2T ]
 *  S. also B. Szeidl, IBVS 903, 1974. [BIBCODE 1974IBVS..903....1S ]