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Description
Slit spectra have been obtained for 82 stars for which the objective-prism radial-velocity catalogue of Stock lists velocities over 130km/s in magnitude. The slit spectra reveal that many of these objects are F-K stars of low metal abundance, including some stars apparently as metal weak as any presently known. Radial velocities were derived from the slit spectra to examine the reliability of the large objective-prism velocities. The slit results confirm that the majority of the stars are indeed of high velocity, but show that the objective-prism technique tends to produce velocities systematically too large in magnitude by about 40km/s. It was also found that a large objective-prism velocity that is of low weight or from spectra near a plate edge is likely spurious. A search of the 10000 entries in Stock's catalogue yields 205 objects with radial-velocity magnitudes over 130km/s. Sixty-three of these velocities are not suspect because of low weight or edge proximity. An additional 14 stars of lower quality prism velocities were confirmed to have high velocities from the slit spectra. The high-velocity stars appear to form two distinct groups: metal-weak F-K stars and spectroscopically normal main-sequence A stars. Slit spectra were obtained on six nights in April 1978 utilizing the Boller and Chivens spectrograph and the Carnegie image tube at the Cassegrain focus of the 1-m Yale telescope at CTIO.
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