Astronomers have detected eight new sources of very high-energy gamma rays in the Milky Way. A paper published in the current issue of the journal Science describes the novel finds, two of which may represent a new class of cosmic-ray source.

Pulsars and supernovae are two of the myriad phenomena in our galaxy that can accelerate electrons or nuclei to produce high-energy emissions. Felix Aharonian of the Max Planck Institute for Nuclear Physics in Germany and his colleagues used the High Energy Stereoscopic System (HESS) of four telescopes in Namibia, Africa, to search the central part of the Milky Way. Scanning the skies for the highest energy gamma-ray emissions, they discovered eight previously unknown sources. Each stretches tens of light-years across and three are associated with nearby supernova remnants. Another three are located near pulsars, the team reports.

For the two remaining newly discovered sources, however, the scientists found no corresponding activity at radio, x-ray or optical wavelengths. "The lack of any counterparts for these two sources suggests the exciting possibility of a new class of 'dark' particle accelerators in the Galaxy," the authors conclude. Future studies with HESS will focus on other parts of the galaxy, searching for similar discoveries.