COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1137

                              Konkoly Observatory
                              Budapest
                              1976 May 31


 THE POSSIBILITY OF THE SEARCH FOR RELATIVISTIC OBJECTS USING
    THE ELLIPSOIDAL VARIABILITY OF THE RUN-AWAY STARS




   Some evidence for the binary nature of the run-away stars
and their connection with relativistic objects appeared recently
(Shklovsky, Astron.J.Letters, USSR, 2, No2, 119, 1976). In this 
connection we propose to search for the periodic optical variability
of these stars in the filter B of the UBV system. The list of the
run-away stars (Blaauw, BAN 15, 265, 1961) is: HD 210839, 24912,
157857, 152408, 203064, 30614, 34078, 149757, 38666, 151397, 149363,
19374, 97991, 197419, 41534, 214930, 216534, 4142, 201910. The
periodic variability of the run-away stars may be connected with
their tidal distortion caused by relativistic objects - neutron
stars or the black holes. The amplitude of this periodic ellipsoidal
light variations may be =< 0.05 and is independent on
wavelength; the period is about some days. It is also interesting
to investigate the physical light variations of the run-away stars
and to compare them with the variations of "ordinary" O-B stars
with small spatial velocity. Note that some run-away stars (for
example mu Col - see Cousins et al., R.O.Bull. No 25, 1961) show small-
amplitude variability which may be caused by the ellipticity of the
optical star. The photometric investigations of run-away stars are
very important and we suggest joint observational efforts in this
field during 1976.




           ANATOLY M. CHEREPASHCHUK, BORIS V. KUKARKIN
           Astronomical Council of the USSR Academy of
                Sciences, Variable Star Bureau