COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1837

                                 Konkoly Observatory
                                 Budapest
                                 1980 September 2

                                 HU ISSN 0374-0676


         PHOTOELECTRIC LIGHT CURVES OF RZ COLUMBAE


   The eclipsing binary system RZ Col (CoD-36deg2177) was discovered
photographically by Hoffmeister (1949). With the exception of the photographic 
data obtained by Hoffmeister (1956), no further work has been done
on this system. For this reason, RZ Col was selected for observation on
eight nights during December 1979. The number two 41cm telescope at Cerro
Tololo Inter American Observatory was used with standard B,V filters and
an RCA 1P21. The comparison star was CoD-36deg2174; CoD-36deg2179 was the
check star.
   The beta Lyrae-type light curve is well defined at each effective wavelength. 
From the observations defining two primary and three secondary
eclipse curves, five epochs of minimum light were determined. These are
listed in Table I.


                   TABLE I


       JD Hel.
       2444200+   Min. (O-C)I (O-C)2
       23.6959     II +0.0017d +0.0001d
       27.6525     II +0.0018 +0.0004
       29.6291     I   0.0000 -0.0011
       32.7396     II +0.0018 +0.0010
       33.5860     I  +0.0004 -0.0004

The times of primary minimum light in Table I and those observed by
Hoffmeister (1956) were introduced into a least squares solution to obtain
the ephemeris

        JD Hel. Min. I = 2434326.2824 + 0.56522725E.
                       +-          15 +-        29 p.e.

This was used to calculate the (O-C)_1 's in Table I. The present observations

                             [FIGURE 1]

indicate a somewhat shorter period, and the following set of light elements,

        JD Hel. Min. I = 2444229.6302 + 0d5651765E,

was used to calculate the (O-C)_2 's in Table 1.
  The B and V light curves of RZ Col, defined by normal points, are shown
in Figure 1 as Delta m versus phase.
   An analysis of the observations is underway. Preliminary work indicated
the eclipses are complete. Spectroscopic observations are urgently needed.



                         BEVERLY B. BOOKMYER
                         DANNY R. FAULKNER
                         Dept. of Physics and Astronomy
                         Clemson University
                         Clemson, SC 29631 USA



References:

Hoffmeister, C. 1949, Astr. Abh. A.N. 12 (1).
------ 1956, Veroff, Sonneberg 3, 3. [BIBCODE 1956VeSon...3....1H ]