COMMISSION 27 OF THE I. A. U.
             INFORMATION BULLETIN ON VARIABLE STARS
                          Number 2272



                                             Konkoly Observatory
                                             Budapest
                                             1983 January 21

                                             HU ISSN 0374-0676

 
        THE PHOTOMETRIC PERIOD OF SZ PICTORIS


  In this short note we derive the photometric period of SZ Pictoris =
HD 39917, which Andersen et al. (1980) had discovered to be variable and
suggested was an RS CVn binary with 'a period of the order of a couple of
days'.
  First we used a period-finding program similar to that of Lafler and
Kinman (1965) to analyze the 16 V magnitudes in Table I of Andersen et al.
between JD 2443931.5 and 2443941.6. The result was 2.45d with an uncertainty
of a few hundredths of a day.


                            [FIGURE 1]



   Then we considered the first two values of V in their table, which
were about 700 days earlier, and the last four values, which were about
200 days later. Analysis showed that all 22 V magnitudes would produce a
coherent light curve with a period of 2.441d, although we admit that there
might have been some ambiguities in phasing together the three groups of
data.
   The light curve is shown in the figure below. Phases are computed
with the ephemeris
         JD 2443931.54 + 2.441d n,                                 (1)
where the initial epoch is a time of minimum light. The amplitude of the
light curve from maximum to minimum is about 0.15mag.






               BRIAN M. BELL
               DOUGLAS S. HALL
               ROBERT L. MARCIALIS

               Dyer Observatory
               Vanderbilt University
               Nashville, Tennessee 37235
               U.S.A.





References:
Andersen, J., Nordstrom, B., and Olsen, E. H. 1980, I.B.V.S. No. 1821.
Lafler, J. and Kinman, T. D. 1965, Ap. J. Suppl. 11, 216. [BIBCODE 1965ApJS...11..216L ]