COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1542

                                  Konkoly Observatory
                                  Budapest
                                  1979 January 31




    5-HOUR LIGHT VARIATIONS OF HD 65953 (28 Mon) ?


    Photoelectric UBV observations are presented of the K4 giant
HD 65953. Used as one of several comparison stars for the study
of variability of HD 67594 it turned out to be variable itself.
    Between January 18 and January 31, 1977 14 observations
were made of HD 65953 relative to HD 67594 using the Bochum
University 61cm telescope at La Silla, Chile. HD 67594 remained
constant to within the internal precision of the photometry,
i.e. 0.003m. Reduction procedures were the same as those described 
by Stift (1978). Plotting the UBV magnitudes versus Julian
Date seems to indicate semiregular behaviour on a time scale
of about 5 days (Fig. 1). Amplitudes are 0.020m in V, 0.025m in
B and 0.030m in U.
    A search for periodicity with the help of a 5 component
Fourier least squares fit leads to a 5 hour period (Fig. 2). The
curve is remarkably smooth and it appears most unlikely that it
is due to chance only. The nightly observing interval of about
1/2 hour makes it impossible to confirm or discard the 5 hour
period.
    The observations lend further support to the conclusion of
Maeder and Rufener (1972) who claim that all K-giants from K5
are variable. We may speculate whether such short-period variations 
are due to oscillations connected with mass loss in K-giants
(Deutsch, 1950), but only spectroscopic observations can provide
the necessary information.



                          M.J. STIFT
                          Institut fur Astronomie
                          Universitats-Sternwarte, Wien



References:

Deutsch, A.J.: 1960, The loss of mass from red giant stars, in
       Stellar Atmospheres, Ed. J.L. Greenstein, Univ.of Chicago
       Press, Chicago, p. 543 [BIBCODE 1960stat.conf..543D ]
Maeder,A. and Rufener, F.: 1972, Astron.Astrophys. 20, 437 [BIBCODE 1972A&A....20..437M ]
Stift, M.J.: 1978, Astron.Astrophys.Suppl. 32, 343 [BIBCODE 1978A&AS...32..343S ]


                     [FIGURE 1]

   Figure 1: Observations of HD 65953 relative to to HD 67594 plotted
   versus J.D. - 2443100.

                     [FIGURE 2]

   Figure 2: Observations of HD 65953 relative to to HD 67594. The
   phases are given by phi = (J.D. - 2443100) 0.207878^-1.