COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1179
                               Konkoly Observatory
                               Budapest
                               1976 September 13




       UBVRI PRIMARY AND SECONDARY ECLIPSE CURVES OF RW TAURI


    RW Tauri, BD+27d623, is the first eclipsing binary system in which
the presence of gas streaming was established, and a gaseous ring around the
B component was postulated by Joy (P.A.S.P. 54, 35, 1942; P.A.S.P. 59, 171,
1947). According to Plavec (B.A.C. 13, 224, 1962) the marked eccentricity
of the spectrographic orbit is probably spurious, resulting from the gas
streaming. However, up to the time of the present observations there was no
direct proof from photometric observations that the true orbit is nearly
circular since the secondary minimum had not been observed.
    The present observations were made in 1967-68 with the Johnson UBVRI
photometer attached to the 0.7 m and the 1.5 m telescopes then housed at the
Catalina Observatory of the University of Arizona. The photometer houses
two cooled photomultiplier tubes. A movable mirror in the light path permits
the directing of the beam to the RCA 1P21 for the UBV observations or to the
RCA 7102 for the RI observations.
    Approximately 250 observations were obtained at each effective wavelength. 
BD+27d628 and BD+27d629 were used as the comparison and check stars,
respectively; and on several nights a network of standard stars was also
observed. Figure 1 shows the light curve as defined by the I observations.
The phases were computed from the ephemeris determined by Maddox (to be
published, 1976), JD Hel. Min. I = 2440160.3771 + 2.7688425d E. The 
observations have not been corrected for the light of the visual companion,
which is at a separation of about 1".
    The observations have been prepared for publication and anyone wishing 
a tabulation prior to publication should contact the author.


                           BEVERLY B. BOOKMYER
                           Dept. Physics & Astronomy
                           Clemson University
                           Clemson, S.C. 29631 USA


                       [FIGURE 1]