Astronomers identify the 514 most powerful objects in the Universe - they don't know what 65 of them are

The Fermi Space Telescope has catalogued the 514 most powerful objects in the Universe, that we know of. Astrophysicists don’t know what over 10% of them are. Why 514?   The idea was to catalog the objects which emit γ-ray sources at energies above 10 GeV. What’s a GeV? It stands for Giga electronvolt, which […]