COMMISSIONS 27 AND 42 OF THE IAU
             INFORMATION BULLETIN ON VARIABLE STARS
                         Number 3934

                                             Konkoly Observatory
                                             Budapest
                                             10 September 1993

                                             HU ISSN 0374 - 0676


           VZ CYGNI: A NEW SPECTROSCOPIC BINARY CEPHEID


  According to the 4th edition of the GCVS. the classical Cepheid VZ Cyg has the
period 4.864453d (period changes have been noted) and varies in the range 
8.60m-9.28m V.
Its binarity was first suspected by Madore and Fernie (1980) from photometric data.
Though some radial velocity measurements are available for the star in the literature
(Joy, 1937; Barnes et al., 1988), the star's spectroscopic binarity, to our knowledge, was
not explicitly announced. Szabados (1991) notes possible gamma-velocity changes but says
that `further radial velocity measurements are necessary to make a firm statement on this
matter'.
  Since 1992 we observe VZ Cyg in the frame of our programme (cf. Gorynya et al., 1912)
of Cepheid radial velocity measurements with Tokovinin's (1987) radial velocity meter.
By early August, 1993 we have acquired 31 V_r measurements and found that VZ Cyg is a
definite spectroscopic binary. Table 1. contains our V_r values, and Fig. 1 shows the radial
velocity curve. Further observations are under way.

                    Table 1
          Radial velocities of VZ Cygni
------------------------------------------------------
JD hel. 244...   V_r   sigma JD hel. 244...  V_r sigma
------------------------------------------------------
8822.510        -33.3   0.5   8869.495       1.6   0.4
8824.511        -14.9   0.5   8870.448     -15.2   0.5
8825.510         -4.8   0.5   8879.518       0.1   0.8
8827.508        -33.9   0.3   8880.436     -26.1   1.8
8830.520         -2.7   0.5   8886.416     -30.0   1.0
8831.505        -15.3   0.5   9191.507      16.3   0.5
8832.476        -33.1   0.5   9194.465      -6.7   0.4
8833.473        -23.4   0.4   9195.490       2.4   0.6
8834.451        -12.4   0.3   9196.490     -17.9   0.6
8838.428        -22.3   0.4   9197.457     -26.4   0.6
8839.464        -11.0   0.4   9198.446     -15.7   0.4
8861.496        -31.5   0.5   9199.457      -4.7   0.5
8862.492        -23.0   0.5   9200.486       5.8   0.5
8863.481        -12.7   0.3   9201.463     -21.5   0.5
8864.451         -3.2   0.3   9202.489     -24.5   0.4
8866.495        -30.3   0.6
------------------------------------------------------

                            [FIGURE 1]

 Figure 1. Radial velocity curve of VZ Cyg from our observations. 
                Dots - 1992, crosses - 1993.

We are grateful to Dr. A. A. Tokovinin for the possibility to use his radial velocity
meter. Thanks are due to the administration and the staff of the Simeiz Department of the
Crimean Observatory for the telescope time and for assistance during observations.   We
also thank Mr. D. I. Neyachenko and Mr. O. S. Ugolnikov who helped at the telescope.


	N. N. SAMUS
	N. A. GORYNYA 			YU. V. KULAGIN
	Institute for Astronomy, 	A. S. RASTORGOUEV
	Russian Acad. Sci 		Sternberg Astronomical Institute
	48, Pyatnitskaya Str., 		13, University Avenue,
	Moscow 109017, Russia 		Moscow 119899, Russia



References:

Barnes IV, T. G., Moffett, T. J., Slovak, M. H.,1988, Ap. J. Suppl., 66, 43 [BIBCODE 1988ApJS...66...43B ]
Gorynya, N. A., Irsmambetova, T. R., Rastorgouev, A. S., Samus, N. N., 1992, Pisma v
   Astronomicheskij Zhurnal, 18, 777 [BIBCODE 1992SvAL...18..316G ]
Joy, A. H., 1937, Ap. J., 86, 379 [BIBCODE 1937ApJ....86..363J ]
Szabados, L., 1991, Comm. Konkoly Obs., No. 96 [BIBCODE 1991CoKon..96..123S ]
                                               [CoKon No. 96]
Tokovinin, A. A., 1987, Soviet Astronomy, 31, 98 [BIBCODE 1987SvA....31...98T ]