COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1527

                                Konkoly Observatory
                                Budapest
                                1978 December 29



         AN ECLIPSING BINARY IN THE FIELD OF omega CEN


    Niss, Jorgensen and Laustsen (1978) have recently published a
list of new variables in the region of the globular cluster NGC 5139
(omega Centauri). Of these stars, one (their number 5, hereafter called NJL 5)
was classed as a definite eclipsing binary.
    A search through the Harvard Observatory plate collection by the
undersigned has located approximately 250 plates with images of NJL 5 from
1893 to 1950, and 14 definite minima from JD 2,413,409.5 (1895) to 2,430,171.2
(1941). The resulting period is 1.376162d, with epoch of minimum at
JD 2,429,787.22d. Fig. 1 shows a light curve of NJL 5 derived from 39
plates (blue emulsion without filter) taken with the Harvard 60-inch
Rockefeller Reflector at Bloemfontein, South Africa between 1933 and 1941.
Comparison stars were taken from the photometry of Cannon and Stobie (1973).
    Although a detailed solution of the light curve for elements has not
been made, the shape suggests that the primary may have a radius appropriate
to a main sequence star. Therefore, at the magnitude derived, NJL 5 is
probably not a member of NGC 5139.



                  MARTHA H. LILLER
                  Harvard-Smithsonian Center for Astrophysics
                  Cambridge, Mass. 02138, U.S.A.



References:

Cannon, R. D. and Stobie, R. S. 1973, Mon. Not. Roy. Astr. Soc. 162, 211. [BIBCODE 1973MNRAS.162..207C ]
Niss, B., Jorgensen, H. E., and Lausten, S. 1978, Astron. Astrophys.
  Suppl. 32, 387. [BIBCODE 1978A&AS...32..387N ]


                        [FIGURE 1]