A Deep Photometric Look at Two of Andromeda's Dwarf Spheroidals: X and
  XVII
  We use deep wide-field photometry from the Large Binocular Camera to study
the stellar and structural properties of the recently discovered Andromeda X
and Andromeda XVII (And X and And XVII) dwarf galaxies. Using the mean apparent
magnitude of the horizontal branch (HB), we derive distances of 621 +- 20 kpc
to And X and 734+- 23 kpc to And XVII, closer by >60 kpc than the previous
estimates which were based on red giant branch (RGB) observations. Thus our
results warrant against the use of the RGB tip method for determining distances
to systems with sparsely populated RGBs, and show how crucial HB observations
are in obtaining accurate distances in systems such as these. We find that And
X is a relatively faint (MV = -7.36), highly elongated (e = 0.48) system at a
distance of 174 +- 62 kpc from Andromeda. And XVII is brighter (MV = -8.61)
with an M31-centric distance of 73 kpc which makes it one of the closest
satellites to Andromeda. Both galaxies are metal-poor: we derive <[Fe/H]>=-2.2
for And X, while And XVII shows <[Fe/H]> = -2.0, consistent with the relation
of higher luminosity dwarfs being more metal- rich. Additionally, both galaxies
show considerable intrinsic spreads in metallicity (0.2 and 0.3 dex for And X
and And XVII respectively), consistent with multiple stellar populations.
