  Recent UV observations of the globular cluster NGC2808 (Brown et al. 2001)
show a significant population of hot stars fainter than the zero-age horizontal
branch (``blue hook'' stars), which cannot be explained by canonical stellar
evolution. Their results suggest that stars which experience unusually large
mass loss on the red giant branch and which subsequently undergo the helium
core flash while descending the white dwarf cooling curve could populate this
region. Theory predicts that these ``late hot flashers'' should show higher
temperatures than the hottest canonical horizontal branch (HB) stars and should
have He- and C-rich atmospheres. As a test of this late hot flasher scenario,
we have obtained and analysed medium resolution spectra of a sample of blue
hook stars in NGC2808 to derive their atmospheric parameters. Using the same
procedures, we have also re-analyzed our earlier spectra of the blue hook stars
in omega Cen (Moehler et al. 2002) for comparison with the present results for
NGC2808. The blue hook stars in these two clusters are both hotter (Teff >
35,000 K) and more helium-rich than canonical extreme HB stars in agreement
with the late hot flasher scenario. Moreover, we find indications for C
enhancement in the three most He-enriched stars in NGC2808. However, the blue
hook stars still show some H in their atmospheres, perhaps indicating that some
residual H survives a late hot flash and then later diffuses to the surface
during the HB phase. We note that the presence of blue hook stars apparently
depends mostly on the total mass of the globular cluster and not so much on its
HB morphology.
