  We present the results of our search for faint Local Group dwarf galaxies in
compact high-velocity clouds (HVCs). We used digitized Palomar Observatory Sky
Survey (POSS) data to examine 1 square degree of sky around each of ~250
northern hemisphere HVCs. The POSS images were processed to remove foreground
stars and large-scale backgrounds, smoothed to enhance arcminute-sized low
surface brightness features, and then compared to the original plates. Using
this technique, we located 60 candidate dwarf galaxies in the ~250 square
degrees that we surveyed. Followup observations of these candidates have
revealed several distant clusters of galaxies and a number of possible Galactic
cirrus clouds, but no Local Group dwarfs. It appears that many of the low
surface brightness features in the sky survey data are plate flaws. The
second-generation red POSS plates are sensitive down to surface brightness
levels of 25-26 magnitudes per square arcsecond, and our followup images
reached 10-sigma limiting magnitudes of R = 21-23 for point sources. Given
these limits, all known Local Group galaxies except four of the very diffuse,
extended dwarf spheroidals located within 100 kpc of the Milky Way would have
been detected had they been in our survey. Therefore, we can rule out the
possibility that these HVCs are associated with normal but faint dwarf
galaxies. If compact HVCs do contain stars, they must have surface brightnesses
> 1 magnitude per square arcsecond fainter than most known Local Group
galaxies.
