Serendipitous discovery of a faint dwarf galaxy near a Local Volume
  dwarf
  A faint dwarf irregular galaxy has been discovered in the HST/ACS field of LV
J1157+5638. The galaxy is resolved into individual stars, including the
brightest magnitude of the red giant branch. The dwarf is very likely a
physical satellite of LV J1157+5638.The distance modulus of LV J1157+5638 using
the tip of the red giant branch (TRGB) distance indicator is 29.82+-0.09 mag (D
= 9.22+-0.38 Mpc). The TRGB distance modulus of LV J1157+5638 sat is
29.76+-0.11 mag (D = 8.95+-0.42 Mpc). The distances to the two galaxies are
consistent within the uncertainties. The projected separation between them is
only 3.9 kpc. LVJ1157+5638 has a total absolute V-magnitude of -13.26+-0.10 and
linear Holmberg diameter of 1.36 kpc, whereas its faint satellite LV J1157+5638
sat has M_V = -9.38+-0.13 mag and Holmberg diameter of 0.37 kpc. Such a faint
dwarf was discovered for the first time beyond the nearest 4 Mpc from us. The
presence of main sequence stars in both galaxies unambiguously indicates the
classification of the objects as dwarf irregulars (dIrrs) with recent or
ongoing star formation events in both galaxies.
