There she blows! A detective case tracking the motion of material ejected from a star to figure out when the star exploded.
Palladino et al. find 13 new hypervelocity star candidates in the galaxy and find they probably do not originate from the center of the galaxy.
HST measurements of stellar proper motions in M31 reveal that the Andromeda galaxy is in radial (head-on collision) orbit towards the Milky Way. The huge strike will happen 4 billion years from now according to the simulations. It will likely affect also the environment of the Sun and the location of the solar system.
In everyday life, measuring distances is easy. In astronomy, however, accurate distance measurements are complicated by a whole host of factors. These authors are improving methods to determine the distance to small M Dwarf stars.