Caption This animation shows a region of the sky centered on the pulsar Geminga. The first image shows the total number of gamma rays detected by Fermi's Large Area Telescope at energies from 8 to ...

The leading suspects include "a supernova remnant called the Monogem Ring; a dying star of the Wolf-Rayet type called γ 2 Velorum; or a pulsar like Vela or Geminga." Previously: • Universe's ...