COMMISSIONS 27 AND 42 OF THE IAU
                 INFORMATION BULLETIN ON VARIABLE STARS
                              Number 4088

                                                      Konkoly Observatory
                                                      Budapest
                                                      19 September 1994

                                                      HU ISSN 0374 - 0676


            UBVR PHOTOMETRY OF THE ECLIPSING BINARY FH ORIONIS



  The close binary system FH Ori (=47.1929=HD 243229, m=10.5-11.5pg, Sp.:A2) was
detected by Hoffmeister (1929) as an eclipsing variable. The binary has been observed
only by visual and photographic methods, while the visual estimations were overwhelming.
Studying the times of minima Szczepanowska (1955) concluded that the variations of
period seemed to be regular and could be represented by a curve having a period of about
18 years and an amplitude of 0.025d.
  According to he GCVS the ephemeris of FH Ori is

             Min I = HJD 2425900.387 + 2.15116d x E.

  Soloviev (1947) observed the variable and found no constant brightness in the primary
minimum (d=0), but the value d>0 in the curves obtained both by Kordilewski and
Szczepanowska (1955).
  We carried out the observations of FH Ori with the 0.6 m telescope at Mt. Maidanak 
in 1989/93 and 137 in U and 243 points were obtained in each B, V, R band.
BD+4d911 (V=10.13m; U-B=012m; B-V=0.42m; V-R=0.26m) and BD+4d913 (V=11.26m;
U-B=0.20m; B-V=0.21m; V-R=0.20m) served as comparison and check stars, respectively.
Having used the above ephemeris we calculated the shift of the normal primary minimum
to 0.9049p. The O-C residuals are plotted in Figure 1. We also used the list of the
minima from Szczepanowska's (1955) report. A long gap between the last observations
of the binary does not permit to see a character of the period change. In order to get
a zero shift for the most recent primary minimum, we suggest that the new period is
equal to 2.15114089d. Photoelectric curves of FH Ori are drawn in Figure 2. We can see a
deep primary minimum and a hardly visible secondary one. The eclipse duration at the
primary minimum is 0.20p and d is equal to zero exactly. We list the main parameters of
the curves of FH Ori in Table 1.

                          Table 1
           
                     V     U-B    B-V    V-R
           Max     11.26   0.21   0.20   0.20
           Min I   12.41   0.21   0.28   0.28
           Min II  11.27    -     0.19   0.14


                           [FIGURE 1]

               Figure 1. O-C diagram for FH Ori

                           [FIGURE 2]

               Figure 2. Light curves of FH Ori



                          Mamnun ZAKIROV
                          Ulugh Beg Astronomical Institute
                          Astronomicheskaya 33, Tashkent
                          700052, Uzbekistan



References:
Hoffmeister, C., 1929, Astron. Nachr., 236, No. 5655, 233 [BIBCODE 1929AN....236..233H ]
Soloviev, A. V., 1947, Astron. Circ., No. 63, 12
Szczepanowska, A., 1955, Acta Astron. Ser. B, 2, 134