  28 hitherto neglected candidates for the Catalogue of Nearby Stars (CNS) were
investigated to verify their classification and to improve their distance
estimates. All targets had at least a preliminary status of being nearby dwarf
stars based on their large proper motions and relatively faint magnitudes.
Better photometric and/or spectroscopic distances were required for selecting
stars which are worth the effort of trigonometric parallax measurements.
  Low-resolution spectra were obtained with NASPEC at the Tautenburg 2m
telescope and with CAFOS at the Calar Alto 2.2m telescope. The spectral types
of M-type stars were determined by direct comparison of the target's spectra
with those of comparison stars of known spectral types observed with the same
instrument. The classification of earlier types was done based on comparison
with published spectral libraries. The majority were classified as M dwarfs
including 11 stars within 25 pc. The fainter component of LDS 1365, previously
thought to form a nearby common proper motion pair, is according to our results
an unrelated high-velocity background star. For several other nearby common
proper motion pairs our distance estimates of the fainter components are in
good agreement with Hipparcos distances of the brighter components. (abridged)

Astrophysics