COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                          Number 963

                                        Konkoly Observatory
                                        Budapest
                                        1975 February 4


            HD 169454 : A POSSIBLE ZETA Aur SYSTEM

HD 169454 was observed photoelectrically in B light with the 16 in.
reflector of Siding Spring Observatory for 13 nights in August and
September 1970 as comparison star for the magnetic variable HD 168814.
    Between JD 2440829.9 and 2440832.9 the luminosity of this star
decreased by 0m.04, while before and after these days it stayed approximately 
constant. This diminution could be explained as due to an eclipse 
of a long period system. The spectral classification B1Ia+ of
HD 169454 by Morgan et al.(1) could support this hypothesis.
    In the following table are given Julian days, mean differences of 
magnitudes B(HD 169454) - B(HD 168815) in the Johnson system, the number
(N) of observations for night and the standard error
s.e. = (Sum(Delta B-average(Delta B))/N (N-1)^(1/2) if N>3.

     JD        average(Delta B)       N    s.e.

2440 811.97        -0.690             1
     812.93        -0.678             4    .002
     813.97        -0.679             4    .001
     815.97        -0.682             3    .003
     817.89        -0.678             4    .001
     818.91        -0.673             4    .001
     819.89        -0.682             1
     829.90        -0.678             6    .003
     832.93        -0.637             3    .002
     834.93        -0.645             5    .001
     835.96        -0.634             2
     836.96        -0.626             2
     840.94        -0.646             2

According to our observations the totality should continue at least
for 8 days.

(1) Morgan, W.W., Code, A.D., Whitford, A.E., 1955, Astrophys.Journ.
    Suppl. 2, 41. [BIBCODE 1955ApJS....2...41M ]



Osservatorio Astronomico dell'Universita
              di  Bologna                       C. BARTOLINI
                                                S. SCARDOVI