Crab Nebula seen to erupt in a super-flare
During the Fermi telescope's monitoring of the outburst, the flare became 30 times more energetic than the nebula’s normal gamma-ray output and about five times more powerful than previous outbursts. Astronomers think that these flares are caused by sudden rearrangements of the magnetic field not far from the neutron star, but exactly where that’s happening still remains a mystery.
The crab nebula is the scattered remains of a massive supernova that was recorded back in 1054 AD. Over the past 1,000 years (almost) it has continued to expand into the amazing object that we see today. It is located 6,500 light-years away in the constellation of Taurus. At the centre of the expanding gas cloud is the remnant core of the original star, a super-compressed neutron star that is around 30km in size and spins at an incredible 30 revolutions per second. As it rotates, the star swings an intense beam of radiation towards the Earth, creating a pulsed emission that is detectable in the radio spectrum, and is typical of spinning neutron stars.