Latest outbursts send theorists scuttling for an explanation
Only last year, scientists were astonished to find that the nebula — a giant cloud 6,500 light-years from Earth with the spinning cinder of an exploded star at its center — had spat out gamma-ray flares that fluctuated on time scales of only a few days (SN: 1/1/11, p. 11).
Last month, however, the nebula outdid itself, says Rolf Buehler of the SLAC National Accelerator Laboratory in Menlo Park, Calif. The Crab hurled gamma-ray flares, more energetic and five times brighter than any previously recorded, that fluctuated over just one to three hours. Buehler announced the findings, based on observations with the Ferm