The radial velocity measurements have been made on the sharpest spectral lines
of the direct and inverted spectra obtained by turning the objective
prism by 180 around the axis of the telescope.
They used the two-axes measuring machine of the
Marseilles Observatory which is accurate to 1
m on each axis. I thank
L. Prévot et J. Peyrin for their help with the measurements.
The exposure time was 2 2 hours for all plates. The plates
are not numerous and of insufficient quality for yielding accurate results.
However a radial velocity larger than 100 km s-1 has been measured
on at least two
different plates for the 7 first stars of Table 1 and
can be considered as certain.
The results are less certain for the 4 following stars (Nos. 8 to 11) for which the spectra are underexposed and the lines broad. They have to be confirmed by further measurements. Star No. 11, contrary to all the others, seems to have a large negative radial velocity, but it is faint and has broad lines.
Star No. 12 has hydrogen lines in emission and its large positive velocity has been mentioned by M. and A. Duflot.
It is clear that the measured stars may have variable radial velocities and that superimpositions on the plates might yield incorrect results. I found it interesting however to mention their existence.
Table 1 gives approximate coordinates for the stars as measured on a 4 times enlargement of Chart 3 of the Canterbury Sky Atlas (Doughty et al. 1972). Figure 1 shows identification charts. The OM numbers (last column) follow those of the stars studied in previous publications (Carozzi 1971, 1974). The radial velocities are too uncertain to be given in the table.
The dates of the plates are given in Table 2.
I thank Mrs. M. Duflot who gave me the plates, and all the personnel of the Marseilles Observatory.
Copyright The European Southern Observatory (ESO)