An international group of astronomers, including George Heald (ASTRON /
RuG), has found a surprising and useful new probe of galactic magnetic
fields. While studying gas halos around nearby galaxies, they were
surprised when detailed studies with the National Science Foundation's
Karl G. Jansky Very Large Array (VLA) showed that one of their subjects
is not a single galaxy, but rather two, nearly perfectly superimposed on
the sky to masquerade as one. The discovery allowed them to use the
alignment to learn otherwise-unobtainable facts about the nearer galaxy.