  We have surveyed Andromeda VI, a dwarf spheroidal galaxy companion to M31,
for variable stars using F450W and F555W observations obtained with the Hubble
Space Telescope. A total of 118 variables were found, with 111 being RR Lyrae,
6 anomalous Cepheids, and 1 variable we were unable to classify. We find that
the Andromeda VI anomalous Cepheids have properties consistent with those of
anomalous Cepheids in other dwarf spheroidal galaxies. We revise the existing
period-luminosity relations for these variables. Further, using these and other
available data, we show that there is no clear difference between fundamental
and first-overtone anomalous Cepheids in a period-amplitude diagram at shorter
periods, unlike the RR Lyrae. For the Andromeda VI RR Lyrae, we find that they
lie close to the Oosterhoff type I Galactic globular clusters in the
period-amplitude diagram, although the mean period of the RRab stars, <P_ab> =
0.588 d, is slightly longer than the typical Oosterhoff type I cluster. The
mean V magnitude of the RR Lyrae in Andromeda VI is 25.29+/-0.03, resulting in
a distance 815+/-25 kpc on the Lee, Demarque, & Zinn distance scale. This is
consistent with the distance derived from the I magnitude of the tip of the red
giant branch. Similarly, the properties of the RR Lyrae indicate a mean
abundance for Andromeda VI which is consistent with that derived from the mean
red giant branch color.
