Maximum speed of hypervelocity stars ejected from binaries
  The recent detection of hypervelocity stars (HVSs) as late-type B-stars and
HVS candidate G/K-dwarfs raises the important question of their origin. In this
Letter, we investigate the maximum possible velocities of such HVSs if they are
produced from binaries which are disrupted via an asymmetric supernova
explosion. We find that HVSs up to ~770 and ~1280 km/s are possible in the
Galactic rest frame from this scenario for these two subclasses of HVSs,
respectively. We conclude that whereas a binary origin cannot easily explain
all of the observed velocities of B-type HVSs (in agreement with their proposed
central massive black hole origin) it can indeed account for the far majority
(if not all) of the recently detected G/K-dwarf HVS candidates.
