Spectroscopic follow-up of UV-excess objects selected from the UVEX
  survey
  We present the results of the first spectroscopic follow-up of 132 optically
blue UV-excess sources selected from the UV-excess survey of the Northern
Galactic Plane (UVEX). The UV-excess spectra are classified into different
populations and grids of model spectra are fit to determine spectral types,
temperatures, surface gravities and reddening. From this initial spectroscopic
follow-up 95% of the UV-excess candidates turn out to be genuine UV-excess
sources such as white dwarfs, white dwarf binaries, subdwarfs type O and B,
emission line stars and QSOs. The remaining sources are classified as slightly
reddened main-sequence stars with spectral types later than A0V. The fraction
of DA white dwarfs is 47% with reddening smaller than E(B-V)<0.7 mag. Relations
between the different populations and their UVEX photometry, Galac- tic
latitude and reddening are shown. A larger fraction of UVEX white dwarfs is
found at magnitudes fainter than g>17 and Galactic latitude smaller than |b|<4
compared to main-sequence stars, blue horizontal branch stars and subdwarfs.
