COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1990

                                   Konkoly Observatory
                                   Budapest
                                   1981 July 13

                                   HU ISSN 0374-0676



         PHOTOELECTRIC OBSERVATIONS OF VZ Cas


  VZ Cas is a Mira-type variable star with a period of 169.28d.
The spectral type of the star is M0e-M3e. The magnitude is
9.3m - 13.3m (Kukarkin et al., 1976).
  The star VZ Cas was observed as comparison for the eclipsing
binary GG Cas along with BD + 55d280. Later on it was found that
this is already listed as a Mira-type variable. Observations
were mainly taken with the 35-cm reflector of the Uttar Pradesh
State Observatory using an unrefrigerated 1P21 photomultiplier
and d.c. techniques. The mean differential magnitudes of VZ Cas
are being reported with BD + 55d280 taken as comparison star. 
The differential magnitudes are listed in Table I.


                 Table I.

     Differential standard magnitudes of VZ Cas


         (VZ Cas-BD+55d280)    (VZ Cas-BD+55d280)
Julian Date                  Julian Date
               B    V                     B       V
2438 722      1.46m 1.20m     2439 068   1.08m   1.15m
     724      1.05  0.88           076   2.00    0.54
     726      1.39  1.11           080   0.77    0.86
     736      1.14  1.01           081   1.57    0.20
     755      1.13 -0.07           083   0.90    1.07
     757      1.21  0.02           086   1.78    0.16
     758      0.81 -0.26           106   1.44    1.25
     760      1.41 -0.17           110   0.97    1.10
     766      1.73  0.17           434   1.66    0.59
     767      1.55  0.10           448   1.69   -0.09
     769      1.21  0.37           777   1.14   -0.16
2439 060      1.15  1.00           792   1.36   -0.18
     066      1.40  1.12      2444 526   2.35    1.28


  On the night of October 13, 1980 VZ Cas and BD + 55d280
were observed along with standard stars in order to get their
magnitudes and colours which are as follows:


      Star          V               B-V

    VZ Cas         12.27m          +1.15m
    BD + 55d280    11.00           +0.08


  During the observing season 1964-1965, VZ Cas was found to
vary by about 1.4m and 0.9m in yellow and blue colours, respectively.
The nightly observations, however, do not show a variation in
the light.             





                     J.B. SRIVASTAVA and C.D. KANDPAL
                     Uttar Pradesh State Observatory,
                     Manora Peak, Naini Tal - 263129
                             India





Reference:
Kukarkin, B.V., Fedorovich, V.P., Frolov, M.S., Kukarkina, N.P.,
  Kurochkin, N.E., Medvedeva, G.L., Perova, N.B. and Pskovsky, Yu.
  P. 1976, Third Supplement to the General Catalogue of Variable
  Stars (3d. ed., Moscow).