COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 396

                              Konkoly Observatory
                              Budapest
                              1969 October 29



        RADIAL VELOCITY OBSERVATIONS OF THE
           ECLIPSING SYSTEM HD 128661

	The star HD 128661 was announced as a probable
eclipsing variable in Information Bulletin  No. 314 by
G. JACKISCH who observed what appeared to be a minimum at
JD 2438906.455. In Information Bulletin No. 365 A. J. Harris
recorded observations of another minimum at JD 2440362.907.
The star is listed as a spectroscopic binary in Wilson's
General Catalogue of Radial Velocities, but no orbit has
been published.
	We have obtained 20 spectrograms of HD 128661 with
a dispersion of 12 A/mm between JD 2440260 and JD 2440353.
The velocities from these plates indicate that the period
is very close to 3.33d, the range being about 150 km/sec. It
seems almost certain from these observations that the number
of cycles between the two minima, referred to above is 437
and that the period is therefore 3.33284d. (In view of the
fact that we see no sign of a second component in our
spectra it appears likely that both Jackisch and Harris have
observed the primary minimum. The uncertainty as to whether
Jackisch's published time of minimum is geocentric or heliocentric
is not significant in our determination of the period.
	There is evidence in our velocity curve of orbital
eccentricity such that the secondary minimum should follow
the primary by 1.51d.


October 20, 1969.

                   W. GORZA and J. F. HEARD,
                   David Dunlap Observatory,
                   Richmond Hill, Ontario, Canada