This plot shows counts of faint blue stars 30,000 light-years from Earth. The center of the plot is the North Galactic Pole. The large overdensity of stars in Virgo appears in red between 60º and 300º galactic longitude. The dashed arc marks the plane containing debris from the Sagittarius dwarf galaxy now being cannibalized by the Milky Way. It's possible the new structure is related to the Sagittarius dwarf, but known debris from this galaxy is 4 times farther away.
Mario Juric, Princeton University / SDSS-II collaboration