COMMISSION 27 OF THE I. A. U.
              INFORMATION BULLETIN ON VARIABLE STARS
                          Number 929

                                      Konkoly Observatory
                                      Budapest
                                      1974 October 4


              THE ORBITAL PERIOD OF RR PICTORIS

    The first photoelectric observations of the exnova RR Pic have
been obtained by van Houten (1966, BAN 18, 439) revealing a "Cepheid-
like" variation with a period near 3.5 hours. Mumford (1971, ApJ 165,
369) confirmed van Houten's period but he was not able to improve it
due to the unknown cycle difference between the two epochs. New 
photoelectric observations with the 1m telescope of the European Southern 
Observatory (La Silla, Chile) in Dec. 1972 (UBV) and in Jan. 1974
(high speed mode, white light) confirm the variations reported above
and render possible the determination of a unique cycle relation 
between all available observations. The resulting elements for the light
maximum of RR Pic are

        HJD (Max) = 2438815.379 + 0.1450255 . E
                            +-3         +-2  (m.e.)

with a mean O-C of 0d.006 for a single observation of a maximum. There
is no indication for systematic deviation among the observing epochs
or for a changing period. The mean amplitude of the lightcurve was
0m.23 but the periodic variation was always superimposed on erratic 
variations up to 0m.1 on a time scale of a few minutes. - A more detailed
discussion of the observations of RR Pic will be published elsewhere.


European Southern Observatory
Casilla 16317, Santiago 9,
Chile
                                                N. VOGT