A team using the MPG/ESO 2.2-metre telescope at the European Southern Observatory's La Silla Observatory, along with other telescopes, has mapped the motions of more than 400 stars up to 13,000 light-years from the Sun. From this new data they have calculated the mass of material in the vicinity of the Sun, in a volume four times larger than ever considered before.
"The amount of mass that we derive matches very well with what we see -- stars, dust and gas -- in the region around the Sun," says team leader Christian Moni Bidin (Departamento de Astronomía, Universidad de Concepción, Chile). "But this leaves no room for the extra material -- dark matter -- that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!"