QUOTE
"If the dark-energy star is big enough, Chapline predicts, any electrons bounced out will have been converted to positrons, which then annihilate other electrons in a burst of high-energy radiation. Chapline says that this could explain the radiation observed from the centre of our galaxy, previously interpreted as the signature of a huge black hole."
Source: http://www.nature.com/news/2005/050328/full/050328-8.html
Interesting, if it's true it means we will be able to study dark energy, providing we get close to one, that is.