  Faint high latitude carbon stars are rare objects commonly thought to be
distant, luminous giants. For this reason they are often used to probe the
structure of the Galactic halo; however more accurate investigation of
photometric and spectroscopic surveys has revealed an increasing percentage of
nearby objects with luminosities of main sequence stars. Aiming at clarifyin
the nature of the ten carbon star candidates present in the General Catalog of
the Second Byurakan Survey we analyzed new optical spectra and photometry and
used astronomical databases available on the web. We verified that two stars
are N-type giants already confirmed by other surveys. We found that four
candidates are M type stars and confirmed the carbon nature of the remaining
four stars; the characteristics of three of them are consistent with an early
CH giant type. The fourth candidate, SBS1310+561 identified with a high proper
motion star, is a rare type of dwarf carbon showing emission lines in its
optical spectrum. We estimated absolute magnitudes and distances to the dwarf
carbon and the three CH stars. Our limited sample confirmed the increasing
evidence that spectroscopy or colour alone are not conclusive luminosity
discriminants for CH$-$type carbon stars .
