  We report on the results of the spectroscopy of 10 objects previously
classified as brown dwarf candidates via RIJHK colors by Eisenbeiss et al.
(2009), who performed deep imaging observations on a 0.4 sq.deg. field at the
edge of the Pleiades. We describe and judge on classification techniques in the
region of M-type stars. To classify and characterise the objects, visual and
near infrared spectra have been obtained with VLT FORS and ISAAC. The spectral
classification was performed using the shape of the spectra as well as spectral
indices that are sensitive to the spectral type and luminosity class of Mtype
stars and late M-type brown dwarfs. Furthermore a spectrophotometric distance
was calculated and compared the distance of the Pleiades to investigate the
membership probability. As a second argument we analyzed the proper motion. The
brown dwarf candidates were found not to be brown dwarfs, but late-K to
mid-M-type dwarf stars. Based on the obtained distance and tabulated proper
motions we conclude that all objects are background dwarf stars.
