COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                         Number 3409

                                            Konkoly Observatory
                                            Budapest
                                            28 December 1989

                                            HU ISSN 0374 - 0676


            PHOTOELECTRIC OBSERVATIONS OF UW Ori

   UW Ori was discovered by Luther (1911), who, however, suggested an 
incorrect period of 0.407902h. Subsequent period studies were reported, on the
basis of photographic observations, by Whitney (1959), Ahnert (1960) and
Todoran (1962), who gave different values as 2.038127, 2.038101 and
1.0080525 days respectively. So far, no photoelectric data of this star
have been published.
   From October 1986 to February 1987 and from October 1987 to January
1988 this star was observed photoelectrically in BV colours at Xinglong
station, Beijing observatory with the 60 cm reflector.
   BD+20d1172 was used as the check star and the coordinates for the 
comparison star are 05h54m58s(1987) and 20d05'12"(1987), as is shown in
Figure 1.
   A total of 567 photoelectric observations was obtained on 18 nights
and three times of minima were determined by Kwee and Van Woerden's (1956)
method. 27 times of minima were used to compute the period of this star.
   The following ephemeris was derived by weighted least squares method:
          JD.Hel(Min I)=2447172.2684+2.03812913d*E
                              +/- 50         47
   Light curves for this star in BV colours are given in Figure 2. O-C
residuals of times of minima are given in Table I and the O-C diagram is
shown in Figure 3. Over this interval no obvious variation of the period
was found.

                              [FIGURE 1]

            Fig.1. Finding chart for the binary UW Ori

                              [FIGURE 2]

            Fig.2. The light curves of UW Ori in BV colours

                              [FIGURE 3]

            Fig.3. The O-C diagram of tomes of minima for UW Ori

            
                Table I. Times of minima of UW Ori
       JD(hel)     E        O-C  weight    method   observer
      2400000+            (days)

     14307.4730 -16125.0  0.0367    1         pg.     Luther
     16172.3240 -15210.0 -0.0004    1         pg.     "
     16871.3910 -14867.0 -0.0117    1         pg.     "
     17198.5130 -14706.5 -0.0095    1         pg.     "
     17235.2430 -14688.5  0.0342    1         pg.     "
     17242.3420 -14685.0 -0.0002    1         pg.     "
     17297.3880 -14658.0  0.0163    1         pg.     "
     17614.3040 -14502.5  0.0032    1         pg.     "
     17668.3340 -14476.0  0.0228    1         pg.     "
     17670.3530 -14475.0  0.0037    1         pg.     "
     18264.4570 -14183.5 -0.0070    1         pg.     "
     18361.2970 -14136.0  0.0219    1         pg.     "
     19013.4450 -13816.0 -0.0314    1         pg.     "
     19058.2740 -13794.0 -0.0413    1         pg.     "
     19068.5020 -13789.0 -0.0039    1         pg.     "
     33657.4500 - 6631.0  0.0158    1         pg.     Ahnert
     35428.5480 - 5762.0 -0.0204    1         pg.     Whitney
     35432.6220 - 5760.0 -0.0227    1         pg.
     35483.6140 - 5735.0  0.0161    1         pg.     "
     35808.6800 - 5575.5  0.0005    1         pg.     "
     35910.5730 - 5525.5 -0.0130    1         pg.     "
     36287.6150 - 5340.5 -0.0240    1         pg.     "
     36558.6720 - 5207.5 -0.0390    1         pg.     "
     36561.7410 - 5206.0 -0.0272    1         pg.     "
     46794.2144 -  185.5  0.0185    2         pe.     Zhang et al.
     47172.2861      0.0  0.0177    2         pe.     "
     47173.2917      0.5  0.0042    2         pe.     "


  From the light curves the star is to be an eclipsing binary of Beta
Lyrae type with 0.78m and 0.54m deep primary and secondary eclipses 
respectively.


ZHANG RONG-XIAN, ZHANG JI-TONG,
LI QI-SHENG, ZHAI DI-SHENG,
ZHANG XIAO-YU

Beijing Observatory
Academia Sinica
Beijing 100080
China


References:

Ahnert, P.: 1960, Mitt. uber Ver. Sterne, No. 643.
Kwee, K.K. and Van Woerden, H.: 1956, Bull. Astron. Inst. Netherl. 12, 327. [BIBCODE 1956BAN....12..327K ]
Luther, W.: 1911, Astron. Nachr., 187, 191. [BIBCODE 1911AN....187Q.191L ]
Todoran, I.: 1962, Studii Cercetari de Astronomie, 7, No. 1, 155.
Whitney, S.: 1959, Astron. J., 64, 258. [BIBCODE 1959AJ.....64..258W ]