COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2395

                                    Konkoly Observatory
                                    Budapest
                                    2 September 1983

                                    HU ISSN 0374-0676


    MAGNETOMETRIC MEASUREMENTS OF THE CARBON  STAR Y CVn


  There are three plausible mechanisms at least allowing to
explain the causes of the light and radial velocity variations
in carbon stars: radial pulsations, circulation of components in
close binaries, and rotation of heterogeneous single stars. The
last hypothesis could be well supported by measuring and detecting 
reasonably strong magnetic fields connected with these 
objects.
The dipole magnetic field of Y CVn was investigated on the
Zeeman spectra taken with the grating spectrograph of the 6 meter
telescope at Zelenchukskaja (Caucasus) using the dispersion of
1.3 nm/mm in the spectral region of 564 to 626 nm. The Zeeman
splitting was measured on 236 absorption lines mostly of molecular
origin. No systematic deviations were found among the various
producers of the individual absorptions. The splitting was very
small and completely drowned in the dispersion of the individual
measurements. One can conclude from it that the magnetic field
of Y CVn, if any, is very weak, and does not exceed the level of
the measuring errors. The mean value of the magnetic induction
was derived to be B = (0.005 +- 0.010) Tesla (in vacuum).





                     M. VETESNIK
        Department of Astronomy, Brno University
              61137 Brno, Czechoslovakia