Ultra-deep imaging with amateur telescopes
  Amateur small equipment has demonstrated to be competitive tools to obtain
ultra-deep imaging of the outskirts of nearby massive galaxies and to survey
vast areas of the sky with unprecedented depth. Over the last decade, amateur
data have revealed, in many cases for the first time, an assortment of
large-scale tidal structures around nearby massive galaxies and have detected
hitherto unknown low surface brightness systems in the local Universe that were
not detected so far by means of resolved stellar populations or HI surveys. In
the Local Group, low-resolution deep images of the Magellanic Clouds with
telephoto lenses have found some shell-like features, interpreted as imprints
of a recent LMC-SMC interaction. In this review, I discuss these highlights and
other important results obtained so far in this new type of collaboration
between high-class astrophotographers and professional astronomers in the
research topic of galaxy formation and evolution.
