Dwarf Spheroidal Galaxies in the M101 group and behind it
  We use images from the Hubble Space Telescope to determine the distances to a
dozen objects with low surface brightness recently observed around the bright
nearby spiral M101. Only two dwarf galaxies, M101-DwA and M101-Dw9, turn out to
be actual satellites of M101 at distances of about 7 Mpc. The other objects are
probably members of a distant group around the S0-galaxies NGC 5485/5473. Based
on the radial velocities and projected separations of the 9 satellites, we
obtain an estimate of $(8.5\pm3.0)\times 10^{11} M_{\odot}$ for the total mass
of M101, which is consistent with a ratio $16\pm6$ for the total mass to the
stellar mass of the galaxy.
