COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 457

                              Konkoly Observatory
                              Budapest
                              1970 July 27

    AUTOCORRELATIVE ANALYSIS OF LIGHT OF DQ Her, UX UMa
                AND RW Tri


        Photoelectric observations of exnovae and similar
stars were repeatedly analysed by means of statistical 
methods (1,2). These analyses were usually carried of 
observations obtained during a few hours. The results of
the autocorrelative analysis of the light variations of
DQ Her (3,4), UX UMa (5,3) and RW Tri (7) are given in the 
present paper. They were obtained by the method described 
in (8), which can be applied to series with gaps. A unite
correlative shift is equal to 0d0001. The maximum shift
equals 0d01. For each of the three variables the analysis
was performed twice: for all the observations and for 
observations that do not include eclipses. In the first case
the autocorrelative function (r) essentially refers to the
eclipse because of much larger disposition of light variations
owing to eclipse. The function obtained is close to a 
harmonic with a period near to the duration of the eclipse.
The autocorrelative analysis of the observations outside
eclipses gives the autocorrelative function of that component 
of the binary which has a larger light dispersion.
        DQ Her: On Fig.1. (a,b) dots show r for two parts of
the series of V observations. The dashed curves are
cosinusoids with period of P = 0d06. freed from the 
stochastic light variations the eclipse is the same for both
parts of the series. On Fig.1 (c,d) the values if r were
obtained after exclusion of the eclipses for V and U observations. 
The dashed curves are exponentials with relaxation 
times of 0d02 and 0d0074 for V and U bands, 
respectively. In addition to the know harmonic variation
with the period 71s71 _+0s68 (9) the autocorrelative
analysis for DQ Her also reveals a pure stochastic light
variation. The relaxation time of this stochastic process
is larger for radiations of longer wave length.
        UX UMa: On Fig.2 (a,b,c) dots show values of r for 
UBV series including eclipses. Dashed curves are cosinusoids
with periods of 0d040 and 0d037.  The eclipse in U is shorter.
This is an argument in favour of the nonatmospheric nature 
of the eclipses. The difference between the eclipse
durations may be caused by larger limb darkening on the 
brighter component in the U band. Curves d and e of Fig.2
represent values of r for UX UMa outside eclipses for V and
B, respectively. The dashed curves are exponentials with

                     [FIGURE 1]  

relaxations times of 0d025 and 0d0056. As well for DQ Her
the light variations outside the eclipses possesses a longer 
relaxation time for radiation of longer wave lengths.
        RW Tri: On Fig.3 (a) dots show values of the r for V
observations including eclipses. The dashed curve is a 
cosinusoid with P = 0d05. On Fig.3 (b) dots show the r 
values outside eclipses. The dashed curve is an exponential
with a relaxation time of 0d055. It refers to the light
variations of that component or a gas nebula which are uneclipsed 
in the primary minimum. That follows from increase of the eclipse 

                     [FIGURE 2]       

depth with decrease of brightness of
RW Tri according to Walker (7). The 60s-period of RW Tri 
that was pointed out previously (9), seems hardly real. Its
appearance may be likely accounted for the that 
observations (7) were carried out in intervals of the

                     [FIGURE 3]

multiples of 1 minute. Pugach obtained during two hours
about 600 observations of RW Tri using the counting
technique. There was not and evidence of the 60 s period.
        Therefore, the three variables have stochastic
components in their light variations. The autocorrelation
functions of these stochastic processes are exponentials.
Their relaxation times are equal to some thousandths of a 
day in B and decrease with wave length.
        It is interesting that r for B observations of
Sco X-1, which has the spectrum of an exnova, is also an 
exponential with relaxation time of 0d3 (10).


                                F.I. LUKATSKAYA and
                                A.F. PUGACH
                            Main Astronomical Observatory
                                        Kiev

        Literature:
	[REFERENCES]

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