By Ron Cowen
Like travelers that come together from different parts of the world, the sun and many of its stellar neighbors have vastly different origins. Although the sun probably formed where it now resides—about halfway between the Milky Way’s core and its outer edge—a substantial fraction of the sun’s neighboring stars may be immigrants from the core, a new study suggests.
To track the motion of nearby stars as they move across the sky, Benoit Famaey of the Free University of Brussels in Belgium and his collaborators used data from the European Space Agency’s Hipparcos satellite, which ended its mission in 1993. The team then used a ground-based telescope to determine the bodies’ motion toward or away form Earth.