By Will Dunham WASHINGTON (Reuters) – Astronomers have detected in the stellar halo that represents the Milky Way’s outer limits a group of stars more distant from Earth than any known within our own galaxy – almost halfway to a neighboring galaxy. The researchers said these 208 stars inhabit the most remote reaches of the Milky Way’s halo, a spherical stellar cloud dominated by the mysterious invisible substance called dark matter that makes itself known only through its gravitational influence. The furthest of them is 1.08 million light years from Earth. A light year is the distance light tr…