COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1633

                                 Konkoly Observatory
                                 Budapest
                                 1979 June 29




     B V OBSERVATIONS OF NOVA CYGNI 1578 (V 1668 Cyg)




     Between 7 Oct. 1978 and 19 Dec. 1978 photoelectric observations 
of the nova were made during 19 evenings even if the weather
was not of high quality. The 75 cm telescope of the Wilhelm Foerster 
Observatory, Berlin, an uncooled 1P21 multiplier, an usual
amplifier and Schott filters BG12+GG13 for the E-band and GG11
for the V-band were used.
     The stars listed in Table 2 and identified in the Figure
served as comparison stars. Table 1 gives the heliocentric Julian
Date, the mean magnitude V and its standard deviation, the mean
colour B-V and its standard deviation and the number of individual
measurements of the nova for each of the 19 evenings.
     Except J.D. 2442828d, all measurements were done within
half an hour. Consequently, nothing could be said about quick
fluctuations as found by Margrave (IAUC 3296, 1978). The observations 
in J.D. 2443828d seem to indicate such short periodic 
fluctuations.




                             U. HOPP
                             Wilhelm Foerster
                             Observatory
                             Munsterdamm 90
                             D-1000 Berlin - 41


                            [FIGURE 1]

  Identification chart of the Nova Cyg 1978, SS Cyg and the
  used comparison stars. South at the top.


              Table 1

Daily means of N Cyg 1978 observations

Date (J.D.)       V             B-V          n

2443789.325d  9.06m+-0.03m   +0.29m+-0.04m 2
790.258       9.08 0.02        0.34 0.04     3
793.271       9.15 0.01        0.16 0.01     2
794.306       9.67 0.02        0.40 0.02     3
795.307       9.64 0.01        0.20 0.01     4
800.377       9.68 0.02        0.22 0.02     2
807.309       9.90 0.01        0.47 0.02     4
808.344       10.10 0.01       0.24 0.03     3
814.206       10.44 0.02       0.52 0.03     2
815.234       10.36 0.02       0.41 0.11     4
828.249       10.51 0.01       0.29 0.02    10
829.274       10.51 0.02       0.45 0.04     2
832.261       10.61 0.02       0.25 0.03     5
833.255       10.63 0.01       0.24 0.01     5
847.245       10.90 0.05       0.16 0.06     3
848.251       10.83 0.02       0.31 0.03     6
850.191       10.99 0.05       0.23 0.06     3
861.221                        0.33 0.11     3
862.240       10.93 0.05       0.33 0.05     2
              
      Table 2
Comparison stars

Star           V     B-V

A             6.21m +0.18m
B             6.72  -0.06
C             9.23  +0.13
D             9.72  +0.54
E             8.47  +1.20
F             10.73 +0.47
G             7.49  +1.84
I             9.57  +0.95
K             11.18 +0.53