COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2010

                                  Konkoly Observatory
                                  Budapest
                                  1981 August 28

                                  HU ISSN 0374-0676

           THE DELTA SCUTI STAR BETA LEONIS




  The star Beta Leonis, included in Frolov's (1970) list of
probable Delta Scuti stars, was observed photoelectrically in the
nights February 7,8 and 24, 1980 with the photometer described
by Piccioni (1972) mounted on the 60 cm telescope of the Bologna
Observatory.
  HR 4535 and HR 4531 were used as comparison stars, but the
latter is probably a slowly variable star, because in all the
colours the mean differences in magnitudes HR 4531-HR 4535 and
HR 4531-Beta Leo are both variable with an amplitude of 0.03m,
while the mean differences Beta Leo-HR 4535 are practically
constant.
  Blue and yellow instrumental differences of magnitudes, 
presented in the figures, show on February 8, 1980 fast light 
variations with an amplitude of about 0.025m in a time scale of the
order of 0.05d.
   The spectral type A3V and Mv=2.0 given by Eggen (1963) put
this star in the H-R diagram at the left border of the Delta
Scuti instability strip (Breger 1979, Fig. 2.).



                          C. BARTOLINI
                          A. DAPERGOLAS
                          A. PICCIONI

                   Istituto di Astronomia dell'Universita
                   C.P. 596, 40100 BOLOGNA-ITALY





References:
Breger, M. 1979, Pub. Astr. Soc. Pac., 91, 5 [BIBCODE 1979PASP...91....5B ]
Eggen, O.J. 1963, Astron. J. 68, 697 [BIBCODE 1963AJ.....68..697E ]
Frolov, M.S. 1970, Inf.Bull.Var.Stars No. 427
Piccioni, A. 1972, Mem. Soc. Astr. It. 43, 159 [BIBCODE 1972MmSAI..43..159P ]


                        [FIGURE 1]
                        [FIGURE 2]