COMMISSION 27 OF THE I.A.U.
               INFORMATION BULLETIN ON VARIABLE STARS
                            Number 1498

                                                      Konkoly Observatory
                                                      Budapest
                                                      1978 November 2


          SHORT PERIOD VARIABILITY OF HD 153747

HD 153747 was observed photoelectrically in B filter with
the 61 cm telescope at the Abrahao de Moraes Observatory-USP.
This star has been used as comparison (SAO 208337) for HD 153919
by Pacheco et al. (1974) who suggested that it could have small
amplitude variations.
   Two series of observations were taken, on 28/29 and 29/30
June 1978. On both nights, variations with amplitude Delta m = ~0.02 mag
and 67 minutes period were present (see figure). HD 153919 was
observed simultaneously and the random fluctuations were
Delta m = ~0.003 mag.

                      [FIGURE 1]

     Phase diagram for the data folded module 67 min.
     Phase zero is JD 2443688.56.

    The magnitude and colors observed by Pacheco et al. (1974)
are: V = 7.41; B-V = 0.05; U-B = -0.20, consistent with catalog
spectral type B9.
   The interpretation for the observed variable behaviour is
not clear. A plausible guess is that HD 153747 is a magnetic
star. Some of these stars present short period, small amplitude
variations (Bahner and Mavridis, 1957; Rakos, 1963; Kurtz, 1978)
superposed on the main period (0.5-200 d). Furthermore, the
spectral type is compatible with this interpretation and with no
other type of classical variable stars of binary systems with
this period.


              J.E. STEINER, F.J. JABLONSKI* and
                      C.D. GNEIDING*

              Instituto Astronomico e Geofisico
                  Universidade de Sao Paulo
                 C.P. 30627 - Sao Paulo - SP.
                          Brasil

* Supported by CNPq



References:

Bahner, K. and Mavridis, L.N., 1957, Z. Astrophys., 41, 254
Kurtz, D.W., 1978, I.B.V.S. No. 1436
Pacheco, J.A. de Freitas, Steiner, J.E. and Quast, G.R., 1974 Astron. &
   Astrophys. 33, 131
Rakos, K.D., 1963, Lowell Obs. Bull. 6, 91