COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1684

                                    Konkoly Observatory
                                    Budapest
                                    1979 October 9



        PHOTOELECTRIC LIGHT CURVES AND PERIOD STUDIES
            OF CC CASSIOPEIAE AND V448 CYGNI





  Photoelectric light curves of CC Cassiopeiae and V448 Cygni were 
obtained during the latter part of 1978 using an uncooled RCA 1P21 
photomultiplier with a standard V filter (Schott GG495) attached to a 32cm
f/15 Cassegrain telescope with all measurements being taken directly
from a microammeter. Comparison stars used were BD + 34d3876 (V448) and
SAO 023846 (CC Cas). The visual magnitudes of these stars were found to
be 9.01 and 7.98 respectively, plus or minus 0.02. The variables were
measured differentially with respect to their comparison stars with
differential extinction being ignored.


               CC Cassiopeiae

  Sixty five estimates were made; the light curve is presented in
Figure 1. The light curve is a Beta Lyrae type and the eclipses appear
to be partial. The tracing paper method shows that the eclipses are 
occurring at phase .817+-.01. Choosing a date near the middle of the 
observing period corresponding to a phase of .817 we have a time of minimum
equal to 2443818.166. Pearce (1927) first discovered CC Cassiopeiae to be
a spectroscopic binary. Its eclipsing nature was discovered photoelectrically 
by Guthnick and Prager (1930). Both papers list elements. The star
was later observed photographically by Gaposchkin (1953), although his

                            [FIGURE 1]

 Figure 1:  Photoelectric Light Curve of CC Cassiopeiae. Magnitude vs. Phase.

paper seems to be in error as he quotes a time of minimum equivalent to
a phase of .77 using Pearce's elements or .69 using Guthnick and Prager's
elements, but his published light curve shows primary minimum occurring at
phase .27. It is likely that Gaposchkin's time of minimum was secondary
and that he used Pearce's elements, implying that the primary minimum
occurred .5 phase earlier than listed. If we now construct an O-C graph
using the above timings of minimum we obtain Figure 2. A regression line
indicates revised elements are:

     Min(Hel) = 2443818.166 + 3.369491*E. (1)

These elements satisfactorily explain the previous work done on this star
with the possible exception of Hilditch and Hill's(1975) work. They 
published a rough photoelectric light curve which shows minima occurring at
about phases .32 and .82. The minimum at phase .32 appears to be slightly
deeper, although the sparse coverage of both minima does not preclude an
interpretation of primary minimum at .82. A primary minimum at .82 in

                             [FIGURE 2]

 Figure 2: O-C graph for CC Cassiopeiae. Residuals in Days vs. Elapsed 
Periods.

1975 is consistent with our elements, whereas a primary minimum at .32
would indicate CC Cassiopeiae has a dynamical period and merits further
study.


                        V448 Cygni

   One hundred and five estimates were made; the light curve is plotted
in Figure 3. Primary minimum occurs at an O-C value of -.064 day. Choosing 
a date near the midpoint of the observations we obtain a time of
minimum equal to 2443750.409.
   V448 Cygni was first discovered to be an eclipsing binary by Wachmann
(1939). In the following years, Ashbrook (1942) obtained a photographic
light curve, established a Beta Lyrae type variation, and determined a set
of period elements. Ashbrook found the eclipses to be total, although the
duration of totality was short. A rough photographic light curve was later

                         [FIGURE 3]

  Figure 3:   Photoelectric Light Curve of V448 Cygni. Magnitude vs. Phase.


published by Smirnov (1946). Wachmann(1948) obtained four additional times
of minimum. The system was observed spectrographically by Petrie (1956) who
concluded that the eclipses must be partial if the spectrographic data
were to be self consistent. using Ashbrook's ten photographic timings,
Wachmann's four photoelectric timings, and our time of minimum to construct
an O-C graph we obtain revised elements:

      Min(Hel) = 2416361.107 + 6.5197162*E. (2)

It would be unwise to conclude that the eclipses are definitely partial
due to the lack of sufficient data at the minima. However, the observations 
do seem to favor this interpretation.                      

   The authors would like to thank S. W. Schultz, Observatory Director,
for his instrumentation work. This research was sponsored in part by
a NASA Viking Prize Grant.




                          PARTICK HARTIGAN

                              and

                          RICHARD P. BINZEL

                          Physics and Astronomy Dept.
                          Macalester College
                          St. Paul, MN 55105



References:

Ashbrook, J. 1942, HB 916, 7
Gaposchkin, S. 1953, HA 113, No. 2
Guthnick, P. and Prager, R. 1930, AN 239, 5713 [BIBCODE 1930AN....239...13G ]
Hilditch, R. and Hill, G. 1975, Mem. RAS 79, 107 [BIBCODE 1975MmRAS..79..101H ]
Pearce, J. 1927, Publ.DAO IV, 67 [BIBCODE 1927PDAO....4...67P ]
Smirnov, M. 1946, VS 6, 13
Wachmann, A. 1939 BZAN 21, 136
Wachmann, A. 1948 Astr.Abh. 11, 25